Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. ORIGINAL MESSAGE:

On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"

>
>No one will be using a wider shift. It wastes bandwidth and is prone to more
>errors.

REPLY:

It's true that wider shift does use more bandwidth, but in fact,
errors are actually reduced, provided you have a receiver and software
which can take advantage of it. Wider shift reduces the deleterious
effects of selective fading.

Narrow shift causes the mark and space to selectively fade together,
where a wider shift causes them to selectively fade differently. If
the RX bandwidth is wide enough to accommodate both and the software
is capable of correctly decoding when only one tone is present,
reception is actually improved.

The 170 Hz shift used by hams is a compromise between selective fading
and crowded bands. Commercial and military stations who care little
about crowded bands commonly use a much wider shift, for good reason.

73, Bill W6WRT
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. ORIGINAL MESSAGE:

On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"

>
>No one will be using a wider shift. It wastes bandwidth and is prone to more
>errors.

REPLY:

It's true that wider shift does use more bandwidth, but in fact,
errors are actually reduced, provided you have a receiver and software
which can take advantage of it. Wider shift reduces the deleterious
effects of selective fading.

Narrow shift causes the mark and space to selectively fade together,
where a wider shift causes them to selectively fade differently. If
the RX bandwidth is wide enough to accommodate both and the software
is capable of correctly decoding when only one tone is present,
reception is actually improved.

The 170 Hz shift used by hams is a compromise between selective fading
and crowded bands. Commercial and military stations who care little
about crowded bands commonly use a much wider shift, for good reason.

73, Bill W6WRT
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. HI all,

As John GW4SKA is currently busy, I am sending this out to remind you all of the BARTG 75Baud Sprint which will take place on Saturday 12 June 2010 from 2000UTC to 2359UTC.

Full rules can be found at http://www.bartg.org.uk/documents/Contests/sprint75/BARTG%20Sprint%2075%20Rules%202010.pdf

For those of you using Writelog, I suggest reading the page put up by Don AA5AU at www.rttycontesting.com/75baudrtty/75baudrtty.html

Users of N1MM and other contest software will need to check on how to set things up for 75Baud RTTY, as it is all too easy to set the Rx side, but not the Tx side.

PLEASE make sure you are receiving AND transmitting at 75Baud, and also PLEASE NOTE that although the speed is 75Baud, the shift remains at 170Hz.

Just choose the BARTG Sprint module for your contest software.

Logs must be received by 30th June 2010 to qualify.
The contest name in your log must read BARTG-SPRINT. The correct Cabrillo format can be found in the sample log on the BARTG website.
Logs must not include any 599 signal reports.
Any incomplete entries will be classified as check logs.

NOTE: In 2009 about half the entries ignored the above e-mail rules for the normal Sprint.
In 2010 you will be disqualified automatically if you do not follow these simple rules.

This contest will run during an off-period of the DL-DX Long Distance contest, so please try and have a go, it should be fun!

Very best 73, and GL

Phil GU0SUP
BARTG Awards Manager
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. ORIGINAL MESSAGE:

On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"

>
>No one will be using a wider shift. It wastes bandwidth and is prone to more
>errors.

REPLY:

It's true that wider shift does use more bandwidth, but in fact,
errors are actually reduced, provided you have a receiver and software
which can take advantage of it. Wider shift reduces the deleterious
effects of selective fading.

Narrow shift causes the mark and space to selectively fade together,
where a wider shift causes them to selectively fade differently. If
the RX bandwidth is wide enough to accommodate both and the software
is capable of correctly decoding when only one tone is present,
reception is actually improved.

The 170 Hz shift used by hams is a compromise between selective fading
and crowded bands. Commercial and military stations who care little
about crowded bands commonly use a much wider shift, for good reason.

73, Bill W6WRT
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. HI all,

As John GW4SKA is currently busy, I am sending this out to remind you all of the BARTG 75Baud Sprint which will take place on Saturday 12 June 2010 from 2000UTC to 2359UTC.

Full rules can be found at http://www.bartg.org.uk/documents/Contests/sprint75/BARTG%20Sprint%2075%20Rules%202010.pdf

For those of you using Writelog, I suggest reading the page put up by Don AA5AU at www.rttycontesting.com/75baudrtty/75baudrtty.html

Users of N1MM and other contest software will need to check on how to set things up for 75Baud RTTY, as it is all too easy to set the Rx side, but not the Tx side.

PLEASE make sure you are receiving AND transmitting at 75Baud, and also PLEASE NOTE that although the speed is 75Baud, the shift remains at 170Hz.

Just choose the BARTG Sprint module for your contest software.

Logs must be received by 30th June 2010 to qualify.
The contest name in your log must read BARTG-SPRINT. The correct Cabrillo format can be found in the sample log on the BARTG website.
Logs must not include any 599 signal reports.
Any incomplete entries will be classified as check logs.

NOTE: In 2009 about half the entries ignored the above e-mail rules for the normal Sprint.
In 2010 you will be disqualified automatically if you do not follow these simple rules.

This contest will run during an off-period of the DL-DX Long Distance contest, so please try and have a go, it should be fun!

Very best 73, and GL

Phil GU0SUP
BARTG Awards Manager
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Comments inline, below...


----- Original Message -----
Sent: Friday, June 11, 2010 11:42 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> ORIGINAL MESSAGE:
>
> On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"
>
>>
>>No one will be using a wider shift. It wastes bandwidth and is prone to
>>more
>>errors.
>
> REPLY:
>
> It's true that wider shift does use more bandwidth, but in fact,
> errors are actually reduced, provided you have a receiver and software
> which can take advantage of it. Wider shift reduces the deleterious
> effects of selective fading.

Agreed about the selective fading.

> Narrow shift causes the mark and space to selectively fade together,
> where a wider shift causes them to selectively fade differently. If
> the RX bandwidth is wide enough to accommodate both and the software
> is capable of correctly decoding when only one tone is present,
> reception is actually improved.

I believe this is where the technical aspect and real-world experience begin
to separate. For example, the Icom Pro III has the special twin passband
filter setting for RTTY, but (as far as I know) it is limited to the 170 Hz
tone
pairs of 2125 and 2295. For larger shifts you have to open up the receiver
bandwidth to capture both tones, allowing more "noise" to enter the system.
I do not know of any recivers that incorporate the twin tone filters like
Icom,
so I am not certain the majority of operators could reduce errors by using
850 Hz shift.

> The 170 Hz shift used by hams is a compromise between selective fading
> and crowded bands. Commercial and military stations who care little
> about crowded bands commonly use a much wider shift, for good reason.

Understood. In addition, it was mentioned the military often have higher
powered transmitters they could call into action when propoagation was
poor. When I started my RTTY "career" in 1964, 850 Hz shift was the
standard, but 170 Hz started gaining in popularity. For a period of time I
had both shifts installed in my TX4B.

It's interesting (to me) that the idea of using 850 Hz shift has become a
topic of discussion. I am curious how this thought was incubated. :-) But
maybe it's just that I've "been there, done that" that makes it a non-issue
in my mind?

I do have a question about the MMTTY software and the AEA PK232,
Kantronics KAM, and other hardware decoders. Do they effectively "fill in"
the missing mark or space tone when selective fading completely takes one
or the other tones out of the audio stream?

Kok Chen has talked about some demodulators that will receive FSK using
a single tone. I always thought this was a specific feature of a higher
quality
demodulator that needed to be enabled.

73 de Bob - KØRC in MN


> 73, Bill W6WRT
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. ORIGINAL MESSAGE:

On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"

>
>No one will be using a wider shift. It wastes bandwidth and is prone to more
>errors.

REPLY:

It's true that wider shift does use more bandwidth, but in fact,
errors are actually reduced, provided you have a receiver and software
which can take advantage of it. Wider shift reduces the deleterious
effects of selective fading.

Narrow shift causes the mark and space to selectively fade together,
where a wider shift causes them to selectively fade differently. If
the RX bandwidth is wide enough to accommodate both and the software
is capable of correctly decoding when only one tone is present,
reception is actually improved.

The 170 Hz shift used by hams is a compromise between selective fading
and crowded bands. Commercial and military stations who care little
about crowded bands commonly use a much wider shift, for good reason.

73, Bill W6WRT
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. HI all,

As John GW4SKA is currently busy, I am sending this out to remind you all of the BARTG 75Baud Sprint which will take place on Saturday 12 June 2010 from 2000UTC to 2359UTC.

Full rules can be found at http://www.bartg.org.uk/documents/Contests/sprint75/BARTG%20Sprint%2075%20Rules%202010.pdf

For those of you using Writelog, I suggest reading the page put up by Don AA5AU at www.rttycontesting.com/75baudrtty/75baudrtty.html

Users of N1MM and other contest software will need to check on how to set things up for 75Baud RTTY, as it is all too easy to set the Rx side, but not the Tx side.

PLEASE make sure you are receiving AND transmitting at 75Baud, and also PLEASE NOTE that although the speed is 75Baud, the shift remains at 170Hz.

Just choose the BARTG Sprint module for your contest software.

Logs must be received by 30th June 2010 to qualify.
The contest name in your log must read BARTG-SPRINT. The correct Cabrillo format can be found in the sample log on the BARTG website.
Logs must not include any 599 signal reports.
Any incomplete entries will be classified as check logs.

NOTE: In 2009 about half the entries ignored the above e-mail rules for the normal Sprint.
In 2010 you will be disqualified automatically if you do not follow these simple rules.

This contest will run during an off-period of the DL-DX Long Distance contest, so please try and have a go, it should be fun!

Very best 73, and GL

Phil GU0SUP
BARTG Awards Manager
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Comments inline, below...


----- Original Message -----
Sent: Friday, June 11, 2010 11:42 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> ORIGINAL MESSAGE:
>
> On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"
>
>>
>>No one will be using a wider shift. It wastes bandwidth and is prone to
>>more
>>errors.
>
> REPLY:
>
> It's true that wider shift does use more bandwidth, but in fact,
> errors are actually reduced, provided you have a receiver and software
> which can take advantage of it. Wider shift reduces the deleterious
> effects of selective fading.

Agreed about the selective fading.

> Narrow shift causes the mark and space to selectively fade together,
> where a wider shift causes them to selectively fade differently. If
> the RX bandwidth is wide enough to accommodate both and the software
> is capable of correctly decoding when only one tone is present,
> reception is actually improved.

I believe this is where the technical aspect and real-world experience begin
to separate. For example, the Icom Pro III has the special twin passband
filter setting for RTTY, but (as far as I know) it is limited to the 170 Hz
tone
pairs of 2125 and 2295. For larger shifts you have to open up the receiver
bandwidth to capture both tones, allowing more "noise" to enter the system.
I do not know of any recivers that incorporate the twin tone filters like
Icom,
so I am not certain the majority of operators could reduce errors by using
850 Hz shift.

> The 170 Hz shift used by hams is a compromise between selective fading
> and crowded bands. Commercial and military stations who care little
> about crowded bands commonly use a much wider shift, for good reason.

Understood. In addition, it was mentioned the military often have higher
powered transmitters they could call into action when propoagation was
poor. When I started my RTTY "career" in 1964, 850 Hz shift was the
standard, but 170 Hz started gaining in popularity. For a period of time I
had both shifts installed in my TX4B.

It's interesting (to me) that the idea of using 850 Hz shift has become a
topic of discussion. I am curious how this thought was incubated. :-) But
maybe it's just that I've "been there, done that" that makes it a non-issue
in my mind?

I do have a question about the MMTTY software and the AEA PK232,
Kantronics KAM, and other hardware decoders. Do they effectively "fill in"
the missing mark or space tone when selective fading completely takes one
or the other tones out of the audio stream?

Kok Chen has talked about some demodulators that will receive FSK using
a single tone. I always thought this was a specific feature of a higher
quality
demodulator that needed to be enabled.

73 de Bob - KØRC in MN


> 73, Bill W6WRT
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 11, 2010, at 10:26 AM, Robert Chudek - K0RC wrote:

> I do have a question about the MMTTY software and the AEA PK232,
> Kantronics KAM, and other hardware decoders. Do they effectively "fill in"
> the missing mark or space tone when selective fading completely takes one
> or the other tones out of the audio stream?


I don't know about the PK232, but the KAM Plus does not appear to do anything other tha usingn an LM358 comparator with a fixed threshold.

ATC (adaptive threshold correction) does not really "fill in" a missing tone. What it does is to bias the threshold level when one of the tones is weaker than the other.

Imagine that you have the demodulated output from two matched filters, one centered on the Mark tone and one centered on the Space tone. These two outputs represents the amplitude at each of the two tones. When both tones are received with equal strengths, an unbiased slicer will simply use look at whether M-S is positive or negative. If it is positive, a Mark is decoded, if it is negative, a space is decoded.

Now, consider when the Space signal has selectively fade by 6 dB (i.e., the amplitude S is now 0.5 of M). You should no longer use the same threshold (0 volts) to determine whether Mark or Space was received. The threshold should be moved to halfway of M-S (which is now M-0.5*S). A simple way of doing this is to use a filtered versions of M and S amplitudes, call them m and s. The decision of whether M or S was received is then the process of comparing M-S against m/2-s/2 instead of to 0. I.e., the slider voltage of an ATC is m/2-s/2 instead of 0.

Notice that this words with Mark only copy (when S = 0) since the threshold for deciding if Mark was received is simply m/2.

In the analog days, the "filter" to get the slower changing 'm' from 'M' is similar to how we used to build AGC circuits (fast attack, slow decay). You can do much better today with digital modems since it is easy to delay the incoming signal so you can get more accurate estimates of m and s.

One of the earliest patents, titled "Variable Decision Threshold Computer" (US Patent 2,999,925, issued September 1961) for ATC is issued to Mr. Elmer Thomas and assigned to Page Communications Engineers, Inc -- Page was very big in military communications.

The patent's Summary says:

"This invention relates generally to frequency shift keying (FSK) receivers and to multiple level AM digital systems and more particularly to a new device usable with such receivers to modify the criteria for determining which of binary signals is being received by shifting the decision threshold, or the signal with respect to a fixed threshold, under changing conditions and upon fading of said signals."

The patent show very understandable waveforms and circuits (tubes, of course :-), and I highly recommend that anyone with interest in RTTY take a look.

The easiest way to get a copy of the patent in PDF form (the USPTO site seems to have a preference for Internet Explorer and old scanned patents like '925 don't work well with some browsers), go to the following site and enter 2999925 as the patent number, click the Fetch button, and it will build a PDF file for you to download:

http://www.pat2pdf.org/

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.

Hi all,
Been some Talk and I have got Software setup.
QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
and another in Reading the NATO standard of 850Hz Shift?

Jeff-N8NOE
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi Jeff,
My take so far is to just chg baud rate from 45 to 75. I saw something awhile back on this subject saying to use 7 bits bit length, but that must have been just talk. At the time I saw it I thought it was a legit config and I saved a 75 baud profile using 7 bits for future use.. guess that was stupid.

Without a whole list of parameters, I think it is probably just baud rate that needs changing for this contest.

73,
Bill N3XL




________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. BTW, here's a little more nostalgia... someone is
selling the "Original and uncut UPI teletype roll of
President John F. Kennedy's assassination."

Bidding starts at a mere $5,000 US!

http://cgi.ebay.com/JFK-John-Kennedy-Assassination-8-Feet-Teletype-/180498298727?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a06897767

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 3:04 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Bob,
With the closure of the ASC's, Minor Trib's ( Autodin , DSTE's ) most of the ACP's, Janap's
probably went by the wayside.
I think either Coltano or Pirmasen in Germany or Italy was the last one closed but had a skeleton
crew at the time I retired.
Interesting that the message system that replaced the ASC's did not last long.

As far as loosing power at 850hz shift RTTY we never worred about that as we could run 40kw from
some FRT-40's (transmitter).
73
charles/kk5oq


------- Original Message -------
Sent : 6/10/2010 4:04:10 AM
Cc :
Subject : RE: Re: [RTTY] BARTG 75 RTTY Sprint?

JAFPUB 14/2004 froze the document at that time but
apparently someone didn't read that bulletin and issued
JAFPUB 18/2006 which dealt with Y2K 2-year dating
issues.

The 20-November-2009 "Last Updated" most likely
applies to the website, not the document itself. I suspect
they added the "Note: This publication is frozen" text
to the website for those who didn't read the two prior
notices.

The nostalgia part was "tape loops" and "Teleprinters".

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Thursday, June 10, 2010 2:20 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Hi all,

sure I do!

We used the LO 15 and LO 133; a bit noisy
but reliable; and we used 170 Hz shift already
back in 1964 with a commercial (cristall-controlled)
HF-RTTY-link.


Wonder why it is that nostalgic since the ACP 126C has
been updated lin November 2009?

May be it's a silly question?

73 Heinz DK7UM



----- Original Message -----
Sent: Thursday, June 10, 2010 4:09 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


Here's the url: http://jcs.dtic.mil/j6/cceb/acps/acp126/

It's an interesting piece of nostalgia dated 1989. The text establishes
military operating procedures for both landline and communication links
using HF. I liked the section where circuit testing would commence by
installing a tape loop and THE QUICK BROWN FOX was transmitted twice with a
second Line Feed intentionally suppressed. This would visually reveal any
circuit problems because of the mis-matched over print. Obviously the
equipment being used would be mechanical TD's (tape distributors) and
Teleprinters in that environment.

Anyone remember the 'RTTY ART' that was created and exchanged "back in the
days"?

73 de Bob - KØRC in MN



----- Original Message -----
Sent: Wednesday, June 09, 2010 6:49 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?



Sure ref: ACP 126C. 850 Hz shift works very well on 2 Mhz military channels

Jafy

On 6/9/2010 4:37 PM, Robert Chudek - K0RC wrote:
> No one will be using a wider shift. It wastes bandwidth and is prone to
> more
> errors.
>
> Do you have a url regarding a "NATO standard 850 Hz Shift"? I've never
> heard
> of it.
>
> 73 de Bob - KØRC in MN
>
>
> ----- Original Message -----
> Sent: Wednesday, June 09, 2010 5:11 PM
> Subject: [RTTY] BARTG 75 RTTY Sprint?
>
>
>
>> Hi all,
>> Been some Talk and I have got Software setup.
>> QUESTION: at the 75 Baud is anyone Changing the Width of the Shift?
>> I have heard 2 Sides of this, 1 to stay at 170/200Hz Shift,
>> and another in Reading the NATO standard of 850Hz Shift?
>>
>> Jeff-N8NOE
>> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > As far as loosing power at 850hz shift RTTY we never worred about
> that as we could run 40kw from
> some FRT-40's (transmitter).

The power problem when going from narrow shift to a wide shift is bad
but not terrible. The reason is that you are keeping the baud rate,
but just widening the separation of the two tones. The matched filter
for each tone remains narrow -- visualize two band pass filters whose
centers are separated by 850 Hz, each one having the equivalent
bandwidth that is equal to about 1/2 the baud rate (but drops off
slowly as 1/f).

Thus, the extra noise bandwidth is not much greater than using 170 Hz
shift, with the baud rates that we're talking about. I.e., and loss
in SNR has already been accomplished by raising the baud rate :-).

The problem of using excessive bandwidth is however a problem. If
everybody uses proper matched filter, you can start overlapping
signals and get along just fine. Notice that you can place quite a
few amateur RTTY of PSK31 signals in between the two tones of that
loud wide shift commercial RTTY that we hear on 30m and we don't
really suffer ill effects -- and they probably have the appropriate
filters to remove the weak gnats in between their two tones, so they
don't suffer either.

To overlap, you need a higher dynamic range receiving system. If you
are trying to copy a weak signal, the stronger signal that is
overlapping must not exceed the dynamic range of the receiver/sound
card/numerical range, etc. Therefore, in general, I don't think it
will work too well.

You can copy using mark-only or space-only of course. But when you do
that, you do lose that 3 dB of SNR which can affect copy of a very
weak station.

A good reason to use a wide shift is to counter the kind of selective
fading that you find on the lower frequency bands.

To see the effect, you can watch very wide signals, for example the
Coast Guard HF-FAX stations like NMC (in Europe, there are DDH and
DDK) or even a wide DominoEX or Olivia signal on a waterfall display.
What you will notice is that when selective fading occurs on the
higher bands, the QSB "notch" is often very narrow in frequency.
Narrower than 170 Hz. When selective fading occurs there, quite
often, only one of your two RTTY tones will be taken out. Thus, the
demodulator's slicer will automatically compensate for losing the more
attenuated tone (albeit at a loss of up to 3 dB in SNR).

The fading "notch" is much broader at the lower HF like 4 MHz (and I
suspect it is even worse at MF frequencies, but I have not found
appropriate signals to test with). When the fade take away both tones
of your signal, then all bets are off. The receiving system now looks
like it is copying a flat fading signal and you have lost the
advantage of using FSK.

73
Chen, W7AY




_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:

> I saw something awhile back on this subject saying to use 7 bits bit
> length, but that must have been just talk. At the time I saw it I
> thought it was a legit config and I saved a 75 baud profile using 7
> bits for future use.. guess that was stupid.

Yes, that was a separate discussion.

It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
terms of (a) the length of time it takes to send a short contest
exchange that contains both numerical shifts and letters shifts, and
(b) for reducing the confusion between USOS and non-USOS.

For the same baud rate, while getting rid of USOS confusion, ASCII (7
bits) takes pretty much the same amount of time to transmit a
"typical" exchange as Baudot (5 bits) in spite of needing more bits
per character, since it does not have to add in a bunch of extra LTRS
and FIGS shift characters for an exchange such as "N3XL 599 03 03
W7AY". Notice that a USOS system would need to transmit 7 extra shift
characters when using Baudot to send that exchange that consists of 19
characters (about 35%).

ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
start + stop (=7 total) so the ASCII over Baudot overhead is 29%.

ASCII has the additional advantage of providing lower case and the
backspace character, but those features are of no use to a contester.

Switching between Baudot and ASCII is independent of changing baud
rates. I.e., you can just as well use 45.45 baud for ASCII.

I believe someone had mentioned that at least one software modem out
there does not automatically switch to ASCII encoding when you select
7 bits on it, so not everyone can just make the switch. The two
programs that work on Mac OS do allow ASCII encoding (fldigi switches
from Baudot to ASCII code when you select 7 bits and cocoaModem has a
separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
time based on the current FCC Part 97 rules; I think the same is
probably true for other countries.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. > I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch.

Yes, that is the MMTTY program that allows you to set bits, stop, and
parity but it does not support an alternate character set. So you're still
sending the Baudot character set no matter what encoding scheme you
select.

73 de Bob - KØRC in MN


----- Original Message -----
Sent: Thursday, June 10, 2010 12:46 PM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> On Jun 9, 2010, at 6/9 5:25 PM, William Smith wrote:
>
>> I saw something awhile back on this subject saying to use 7 bits bit
>> length, but that must have been just talk. At the time I saw it I
>> thought it was a legit config and I saved a 75 baud profile using 7
>> bits for future use.. guess that was stupid.
>
> Yes, that was a separate discussion.
>
> It was to compare ASCII RTTY (7 bits) with Baudot RTTY (5 bits) in
> terms of (a) the length of time it takes to send a short contest
> exchange that contains both numerical shifts and letters shifts, and
> (b) for reducing the confusion between USOS and non-USOS.
>
> For the same baud rate, while getting rid of USOS confusion, ASCII (7
> bits) takes pretty much the same amount of time to transmit a
> "typical" exchange as Baudot (5 bits) in spite of needing more bits
> per character, since it does not have to add in a bunch of extra LTRS
> and FIGS shift characters for an exchange such as "N3XL 599 03 03
> W7AY". Notice that a USOS system would need to transmit 7 extra shift
> characters when using Baudot to send that exchange that consists of 19
> characters (about 35%).
>
> ASCII has 7 bits + start + stop (=9 total) while Baudot has 5 bits +
> start + stop (=7 total) so the ASCII over Baudot overhead is 29%.
>
> ASCII has the additional advantage of providing lower case and the
> backspace character, but those features are of no use to a contester.
>
> Switching between Baudot and ASCII is independent of changing baud
> rates. I.e., you can just as well use 45.45 baud for ASCII.
>
> I believe someone had mentioned that at least one software modem out
> there does not automatically switch to ASCII encoding when you select
> 7 bits on it, so not everyone can just make the switch. The two
> programs that work on Mac OS do allow ASCII encoding (fldigi switches
> from Baudot to ASCII code when you select 7 bits and cocoaModem has a
> separate "ASCII RTTY" mode). Anyone can experiment with ASCII at any
> time based on the current FCC Part 97 rules; I think the same is
> probably true for other countries.
>
> 73
> Chen, W7AY
>
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. ORIGINAL MESSAGE:

On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"

>
>No one will be using a wider shift. It wastes bandwidth and is prone to more
>errors.

REPLY:

It's true that wider shift does use more bandwidth, but in fact,
errors are actually reduced, provided you have a receiver and software
which can take advantage of it. Wider shift reduces the deleterious
effects of selective fading.

Narrow shift causes the mark and space to selectively fade together,
where a wider shift causes them to selectively fade differently. If
the RX bandwidth is wide enough to accommodate both and the software
is capable of correctly decoding when only one tone is present,
reception is actually improved.

The 170 Hz shift used by hams is a compromise between selective fading
and crowded bands. Commercial and military stations who care little
about crowded bands commonly use a much wider shift, for good reason.

73, Bill W6WRT
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. HI all,

As John GW4SKA is currently busy, I am sending this out to remind you all of the BARTG 75Baud Sprint which will take place on Saturday 12 June 2010 from 2000UTC to 2359UTC.

Full rules can be found at http://www.bartg.org.uk/documents/Contests/sprint75/BARTG%20Sprint%2075%20Rules%202010.pdf

For those of you using Writelog, I suggest reading the page put up by Don AA5AU at www.rttycontesting.com/75baudrtty/75baudrtty.html

Users of N1MM and other contest software will need to check on how to set things up for 75Baud RTTY, as it is all too easy to set the Rx side, but not the Tx side.

PLEASE make sure you are receiving AND transmitting at 75Baud, and also PLEASE NOTE that although the speed is 75Baud, the shift remains at 170Hz.

Just choose the BARTG Sprint module for your contest software.

Logs must be received by 30th June 2010 to qualify.
The contest name in your log must read BARTG-SPRINT. The correct Cabrillo format can be found in the sample log on the BARTG website.
Logs must not include any 599 signal reports.
Any incomplete entries will be classified as check logs.

NOTE: In 2009 about half the entries ignored the above e-mail rules for the normal Sprint.
In 2010 you will be disqualified automatically if you do not follow these simple rules.

This contest will run during an off-period of the DL-DX Long Distance contest, so please try and have a go, it should be fun!

Very best 73, and GL

Phil GU0SUP
BARTG Awards Manager
_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. Comments inline, below...


----- Original Message -----
Sent: Friday, June 11, 2010 11:42 AM
Subject: Re: [RTTY] BARTG 75 RTTY Sprint?


> ORIGINAL MESSAGE:
>
> On Wed, 9 Jun 2010 18:37:33 -0500, "Robert Chudek - K0RC"
>
>>
>>No one will be using a wider shift. It wastes bandwidth and is prone to
>>more
>>errors.
>
> REPLY:
>
> It's true that wider shift does use more bandwidth, but in fact,
> errors are actually reduced, provided you have a receiver and software
> which can take advantage of it. Wider shift reduces the deleterious
> effects of selective fading.

Agreed about the selective fading.

> Narrow shift causes the mark and space to selectively fade together,
> where a wider shift causes them to selectively fade differently. If
> the RX bandwidth is wide enough to accommodate both and the software
> is capable of correctly decoding when only one tone is present,
> reception is actually improved.

I believe this is where the technical aspect and real-world experience begin
to separate. For example, the Icom Pro III has the special twin passband
filter setting for RTTY, but (as far as I know) it is limited to the 170 Hz
tone
pairs of 2125 and 2295. For larger shifts you have to open up the receiver
bandwidth to capture both tones, allowing more "noise" to enter the system.
I do not know of any recivers that incorporate the twin tone filters like
Icom,
so I am not certain the majority of operators could reduce errors by using
850 Hz shift.

> The 170 Hz shift used by hams is a compromise between selective fading
> and crowded bands. Commercial and military stations who care little
> about crowded bands commonly use a much wider shift, for good reason.

Understood. In addition, it was mentioned the military often have higher
powered transmitters they could call into action when propoagation was
poor. When I started my RTTY "career" in 1964, 850 Hz shift was the
standard, but 170 Hz started gaining in popularity. For a period of time I
had both shifts installed in my TX4B.

It's interesting (to me) that the idea of using 850 Hz shift has become a
topic of discussion. I am curious how this thought was incubated. :-) But
maybe it's just that I've "been there, done that" that makes it a non-issue
in my mind?

I do have a question about the MMTTY software and the AEA PK232,
Kantronics KAM, and other hardware decoders. Do they effectively "fill in"
the missing mark or space tone when selective fading completely takes one
or the other tones out of the audio stream?

Kok Chen has talked about some demodulators that will receive FSK using
a single tone. I always thought this was a specific feature of a higher
quality
demodulator that needed to be enabled.

73 de Bob - KØRC in MN


> 73, Bill W6WRT
> _______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 11, 2010, at 10:26 AM, Robert Chudek - K0RC wrote:

> I do have a question about the MMTTY software and the AEA PK232,
> Kantronics KAM, and other hardware decoders. Do they effectively "fill in"
> the missing mark or space tone when selective fading completely takes one
> or the other tones out of the audio stream?


I don't know about the PK232, but the KAM Plus does not appear to do anything other tha usingn an LM358 comparator with a fixed threshold.

ATC (adaptive threshold correction) does not really "fill in" a missing tone. What it does is to bias the threshold level when one of the tones is weaker than the other.

Imagine that you have the demodulated output from two matched filters, one centered on the Mark tone and one centered on the Space tone. These two outputs represents the amplitude at each of the two tones. When both tones are received with equal strengths, an unbiased slicer will simply use look at whether M-S is positive or negative. If it is positive, a Mark is decoded, if it is negative, a space is decoded.

Now, consider when the Space signal has selectively fade by 6 dB (i.e., the amplitude S is now 0.5 of M). You should no longer use the same threshold (0 volts) to determine whether Mark or Space was received. The threshold should be moved to halfway of M-S (which is now M-0.5*S). A simple way of doing this is to use a filtered versions of M and S amplitudes, call them m and s. The decision of whether M or S was received is then the process of comparing M-S against m/2-s/2 instead of to 0. I.e., the slider voltage of an ATC is m/2-s/2 instead of 0.

Notice that this words with Mark only copy (when S = 0) since the threshold for deciding if Mark was received is simply m/2.

In the analog days, the "filter" to get the slower changing 'm' from 'M' is similar to how we used to build AGC circuits (fast attack, slow decay). You can do much better today with digital modems since it is easy to delay the incoming signal so you can get more accurate estimates of m and s.

One of the earliest patents, titled "Variable Decision Threshold Computer" (US Patent 2,999,925, issued September 1961) for ATC is issued to Mr. Elmer Thomas and assigned to Page Communications Engineers, Inc -- Page was very big in military communications.

The patent's Summary says:

"This invention relates generally to frequency shift keying (FSK) receivers and to multiple level AM digital systems and more particularly to a new device usable with such receivers to modify the criteria for determining which of binary signals is being received by shifting the decision threshold, or the signal with respect to a fixed threshold, under changing conditions and upon fading of said signals."

The patent show very understandable waveforms and circuits (tubes, of course :-), and I highly recommend that anyone with interest in RTTY take a look.

The easiest way to get a copy of the patent in PDF form (the USPTO site seems to have a preference for Internet Explorer and old scanned patents like '925 don't work well with some browsers), go to the following site and enter 2999925 as the patent number, click the Fetch button, and it will build a PDF file for you to download:

http://www.pat2pdf.org/

73
Chen, W7AY

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___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe. On Jun 11, 2010, at 11:49 AM, Kok Chen wrote:

> I.e., the slider voltage of an ATC is m/2-s/2 instead of 0.
>
> Notice that this words with Mark only copy (when S = 0) since the threshold for deciding if Mark was received is simply m/2.

Gak! The above should read:

> I.e., the SLICER voltage of an ATC is m/2-s/2 instead of 0.
>
> Notice that this WORKS with Mark only copy (when S = 0) since the threshold for deciding if Mark was received is simply m/2.

73
Chen, W7AY

_______________________________________________
___________________________________________________

Posted on the RTTY mailing list. Go to http://lists.contesting.com/mailman/listinfo/RTTY to subscribe.