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  #1  
09-06-2011 06:20 AM
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Hi Doug, KA9DLP

Hold the RX steady and adjust the TX for doppler.This is what I did
manually from OSCAR-6 and I do actually on VO-52, FO-29 and
OSCAR-7

73" de

i8CVS Domenico

----- Original Message -----
From: "Douglas Phelps" <>
To:
Sent: Thursday, June 09, 2011 2:59 AM
Subject: [amsat-bb] SSB Operation on the satellites.


I am new to the satellites. Got to where I can hear my downlink if the bird
is
higher than 15 degrees. My question is about handling the doppler shift.

If you do not have a sat program automatically correcting you rig frequency,
what is the most common or preffered technique? 1 - Hold the TX steady and
adj
the RX for doppler or 2- Hold the RX steady and adjust the TX for doppler? I
know this must be a basic question but I am learning. Thanks,

Doug
K9DLP
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  #2  
09-06-2011 06:27 AM
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At 10:59 AM 6/9/2011, Douglas Phelps wrote:

>If you do not have a sat program automatically correcting you rig frequency,
>what is the most common or preffered technique? 1 - Hold the TX
>steady and adj
>the RX for doppler or 2- Hold the RX steady and adjust the TX for doppler? I
>know this must be a basic question but I am learning. Thanks,

Adjust the higher frequency of the two you're using.

73 de VK3JED / VK3IRL
http://vkradio.com

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  #3  
09-06-2011 06:37 AM
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> I am new to the satellites.  Got to where I can hear my downlink if the
> bird is
> higher than 15 degrees.  My question is about handling the doppler shift.
>
> If you do not have a sat program automatically correcting you rig
> frequency,
> what is the most common or preffered technique?  1 - Hold the TX steady
> and adj
> the RX for doppler or 2- Hold the RX steady and adjust the TX for
> doppler?  I
> know this must be a basic question but I am learning.  Thanks,
>
> Doug
> K9DLP

Hi!

Good question.

Hold the TX steady and adjust the RX. If You adjust TX, the other guy have
to adjust also his RX and then his TX... a mess.
It is much easier if everybody adjust only his own RX and keeps TX steady.

73
Jari OH3UW


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  #4  
09-06-2011 10:33 AM
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Hi Doug,


Here is the best article on the subject with an explanation
of why and what to do:


http://www.amsat.org/amsat/features/one_true_rule.html


Welcome to satellites!


73,
Tony AA2TX
AMSAT, VP Engineering


---
----- Original Message -----
From: "Douglas Phelps" <>
To: amsat-
Sent: Wednesday, June 8, 2011 8:59:51 PM
Subject: [amsat-bb] SSB Operation on the satellites.

I am new to the satellites. Got to where I can hear my downlink if the bird is
higher than 15 degrees. My question is about handling the doppler shift.

If you do not have a sat program automatically correcting you rig frequency,
what is the most common or preffered technique? 1 - Hold the TX steady and adj
the RX for doppler or 2- Hold the RX steady and adjust the TX for doppler? I
know this must be a basic question but I am learning. Thanks,

Doug
K9DLP
_______________________________________________
Sent via AMSAT-. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________
Sent via AMSAT-. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
)

  #5  
09-06-2011 11:23 AM
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Hi Satelliters,
 
Might cause some flames with this  but here goes:
 
With a good few years of operating on the SSB sats, AO's-10,13,40, RS10,
FO-20,FO-29 and 98 countries confirmed I can agree totally with the "one true
rule" in theory. When stations at each end of the QSO use the method it works
flawlessly, I have done it with QSO partners using Fod track and with Instantrak
computer Doppler correction, but there is the problem.
 
Many of the stations that you want to work will be using manual tuning methods,
so as you maintain your frequencies at the satellite, according to the rule,
your QSO partner will have to search for you. Then when its your turn to
transmit he will have to search for you.

 
The practical solution that I and I believe most of the ops. I have worked seem
to use is to have short overs and to adjust frequencies the TX to try and keep
the QSO in a fixed spot on the receiver.
 
Following the other "often recommended" method of adjusting the higher frequency
irrespective of its function, up link or down link, cause QSO's to drift across
the pass band causing problems for other users.
 
The other point worth making for newcomers to the SSB birds is to start on the
easy passes/satellites first to get the knack of manual tuning. For example, try
VO-52 with its 2m downlink, and to pick low elevation passes where the rate of
change of frequency due to Doppler shift is less. Don't expect to get it right
with near overhead passes of FO-29 until you have delevop  your skills.
 
We were all beginners once so don't be afraid to have a  go and make a few
mistakes.
I am pleased to say that in my experience the SSB satellites have a great user
community who maintain high operating standard and welcome new ops.
 
Have fun on the birds
 
73 John G7HIA
 
Lamenting the loss of our lovely HEO birds, Happy Days !!
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  #6  
09-06-2011 12:08 PM
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A rookie observation….

That article was written in 1994—well prior to the state of the art in full doppler correction. I use MacDoppler for adjusting the VFOs and it happily adjusts both of them. The ONLY time I run into a problem where the received station is moving is when it is clear someone is NOT using full doppler correction.

I would humbly submit that this being 2011 and both SatPC32 and MacDoppler handle full doppler correction, the exception should be the One Tune Rule and the norm should be full doppler correction. I know that when I work someone that is also using full doppler correction, it is a joy as the radio just happily stays tuned and we move during the whole pass.

Is the state of the art still such that we are all using radios that do not support full doppler correction?

I will put my flame suit on now…

73,

Tom


Tom Schaefer, NY4I

EL88pb
Monitoring EchoLink node KJ4FEC-L 489389
DSTAR Capable APRS: NY4I-15



On Jun 9, 2011, at 6:23 AM, John Heath wrote:

> Hi Satelliters,
>
> Might cause some flames with this but here goes:
>
> With a good few years of operating on the SSB sats, AO's-10,13,40, RS10,
> FO-20,FO-29 and 98 countries confirmed I can agree totally with the "one true
> rule" in theory. When stations at each end of the QSO use the method it works
> flawlessly, I have done it with QSO partners using Fod track and with Instantrak
> computer Doppler correction, but there is the problem.
>
> Many of the stations that you want to work will be using manual tuning methods,
> so as you maintain your frequencies at the satellite, according to the rule,
> your QSO partner will have to search for you. Then when its your turn to
> transmit he will have to search for you.
>
>
> The practical solution that I and I believe most of the ops. I have worked seem
> to use is to have short overs and to adjust frequencies the TX to try and keep
> the QSO in a fixed spot on the receiver.
>
> Following the other "often recommended" method of adjusting the higher frequency
> irrespective of its function, up link or down link, cause QSO's to drift across
> the pass band causing problems for other users.
>
> The other point worth making for newcomers to the SSB birds is to start on the
> easy passes/satellites first to get the knack of manual tuning. For example, try
> VO-52 with its 2m downlink, and to pick low elevation passes where the rate of
> change of frequency due to Doppler shift is less. Don't expect to get it right
> with near overhead passes of FO-29 until you have delevop your skills.
>
> We were all beginners once so don't be afraid to have a go and make a few
> mistakes.
> I am pleased to say that in my experience the SSB satellites have a great user
> community who maintain high operating standard and welcome new ops.
>
> Have fun on the birds
>
> 73 John G7HIA
>
> Lamenting the loss of our lovely HEO birds, Happy Days !!
> _______________________________________________
> Sent via AMSAT-. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb


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  #7  
09-06-2011 01:18 PM
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It's certainly the case that many people operate "out in the field" and do not have a computer available.
My radios are not computer controlled, even in the shack.

On 09-Jun-11 11:08, Tom Schaefer, NY4I wrote:

> Is the state of the art still such that we are all using radios that do not support full doppler correction?
>
_______________________________________________
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  #8  
09-06-2011 01:35 PM
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Certainly desirable Tom, but I've been in Amsat and on the birds since the
'70s and it wasn't until the last couple of years that I got my PC hooked
to my FT-736R! And then just this year to get it hooked to my FT-817 (IF)
radio.

I will say that there's nothing better than PC doppler and rotator
control, having used 3 hands many times in the past. I would be a
terrible drummer! But for all fairness, there are a number of reasons
that one may not have PC aided doppler correction so the one true rule
still holds good.

Not a flame, just another opinion. I'm sure this thread will get some
mileage!

73,
Jerry
NØJY

> A rookie observation….
>
> That article was written in 1994—well prior to the state of the art in
full doppler correction. I use MacDoppler for adjusting the VFOs and it
happily adjusts both of them. The ONLY time I run into a problem where the
> received station is moving is when it is clear someone is NOT using full
doppler correction.
>
> I would humbly submit that this being 2011 and both SatPC32 and
MacDoppler
> handle full doppler correction, the exception should be the One Tune
Rule
> and the norm should be full doppler correction. I know that when I work
someone that is also using full doppler correction, it is a joy as the
radio just happily stays tuned and we move during the whole pass.
>
> Is the state of the art still such that we are all using radios that do
not support full doppler correction?
>
> I will put my flame suit on now…
>
> 73,
>
> Tom
>





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  #9  
09-06-2011 03:09 PM
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I always varied the transmit.

This way the person I'm talking to as well as any other listeners are
all on the same freq listening.

Growing up on the birds when you had to twist the BIG knob to keep
everyone on freq is not not a big deal. And to this day i still don't
know why it seems to be a problem now days.

It all just takes practice. just like in field day coming up our club
tries to get the non HF users to come out and try it. and at times it's
incredibly painful to watch the guy that operates "Channelized" radios.

IE: 2 meter FM

How it will take them minutes to finally be within 500Hz of being on
freq of a ssb signal. And even then most of the time they will be
calling someone when it's obvious they are no where near on freq. then
it's twiddling the big knob again going right past on freq spot and
again try again off freq. Where a seasoned operator will tune them in
in 1/2 a sec coming in from one side and stop dead on freq.

it all just takes time on the air.

simple.

Joe WB9SBD

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 6/9/2011 7:18 AM, Nigel Gunn G8IFF/W8IFF wrote:
> It's certainly the case that many people operate "out in the field" and do not have a computer available.
> My radios are not computer controlled, even in the shack.
>
> On 09-Jun-11 11:08, Tom Schaefer, NY4I wrote:
>
>> Is the state of the art still such that we are all using radios that do not support full doppler correction?
>>
> _______________________________________________
> Sent via AMSAT-. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
_______________________________________________
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  #10  
09-06-2011 03:35 PM
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OK my brain may be playing tricks, but if you vary only your transmit
frequency such that you always hear yourself on the same downlink
frequency, isn't it true that the other station may not necessarily be
hearing you on the same downlink frequency and is chasing you anyway?
Your doppler is +5kHz (for example) on the receive, the bird is just about
to pass overhead of me though so my receive ferquency goes rapidly from
+2kHz to -5kHz, your transmit tuning has no relation at all to what
frequency I am listening on. Then the bird goes past you and you suddenly
switch down 5kHz, so I have to follow you on my receive.

Or am I nuts? (Quite possible, come see where I work and you will
understand!)

Jerry
NØJY

> I always varied the transmit.
>
> This way the person I'm talking to as well as any other listeners are
> all on the same freq listening.
>



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