[amsat-bb] Re: Doppler Tuning Convention Question (summary)

Michael Tondee mat_62 at netcommander.com
Tue Jun 1 12:53:48 PDT 2010

In a perfect world, everyone would be using full doppler control via 
computer. As we can see from this discussion, it's not a perfect world. 
During the time that I had the equipment to operate the linear birds I 
found hooking up in a QSO with another station who was using full 
doppler  tuning by computer also was quite an enjoyable experience. Even 
"reading the mail" while two other gents were in contact on full doppler 
was fun. Not so if I came upon a station who was using manual tuning 
while I was trying to let my computer do the work. I had to chase him 
all over the passband and often lost stations completely that way. I 
didn't fare much better with manual tuning. I guess I never really 
learned it like some of the "old hands" have.
  When I can finally afford the V/U unit for my new Flex and get back on 
linear birds it would be my hope that everyone who was in a base station 
setup would be using full doppler control via computer. It baffles me 
why anyone wouldn't, it makes life so much easier.
  I do understand why portable stations like Tim would not be using full 
doppler and I have no problem with that. I guess I just need to learn 
how to manually tune in that situation.
Michael W4HIJ
On 6/1/2010 12:14 PM, John Belstner wrote:
> Thanks to everyone that responded.
> For those that have been on the list for years this thread may be a dull rerun, but as a newbie, the information is useful.
> > From everyones responses, it appears that indeed there are currently two conventions:
> 1. Full Doppler CAT tuning
> 2. Manually tuning the higher frequency while keeping the lower fixed
> I know that operators have been successfully using convention #2 for years so this is my lack of sat operating experience talking here, but just looking at the math it seems that it would be difficult for two stations with different velocity vectors to the satellite to communicate without at least one of them adjusting both TX and RX.  I need to try this for myself I guess.
> One thing I did notice is that when operating Full Doppler CAT tuning I was only able to successfully track other operators who were doing the same.
> Cheers,
> 73, John W9EN
> DM13le
> _______________________________________________

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