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Re: Re: One true rule in 2004...


As we look forward to Echo this summer and to more S band downlinks, I 
would suggest that now is a good time to be thinking about enhancing your 
satellite station capability. Most of us use our computers for antenna 
movement and many of us do have radios capable of computer control (even in 
a write-only mode). Why don't we use our computer to free up some of our 
time so we can enjoy the qso.

For those of you just getting S band capability in preparation for Echo, 
listen to UO-11 and try to track its beacon to see how busy you are even 
without moving your antennas manually or keeping your transmitter also in 
track. Automated doppler tracking is needed.

There are at least several good solutions in software, including my own 
W6IHG Radio Tuner, that will get you there.

Let's hear more stations staying on frequency using doppler tracking with Echo.

Jerry, W6IHG

At 10:16 PM 5/2/2004 -0500, Wayne Estes W9AE wrote:
>Freeman wrote:
>How many folks today are using computer controlled doppler adjustments
>with their radios?
>If computer control is not universal yet.  How many folks are following
>the alternative outlined by KB5MU to tune the radio with the highest
>I noticed on SO-50, FO-20, and FO-29 that QSOs seem to drift up and down
>which would suggest that folks are still doing manual adjustments but
>following different rules for making those adjustments.
>Wayne replies:
>I use computer-controlled uplink/downlink Doppler tuning (SatPC32), but it
>seems like the majority of people on the satellites don't.  It's a shame
>because there are several programs that allow one to get automatic Doppler
>tuning essentially for free (for the cost of a serial cable).
>Some satellite operators use old radios that don't have a computer
>interface, or have a "write only" computer interface which is not suitable
>for "transparent Doppler tuning".  And some satellite operators use multiple
>radios which are somewhat more difficult to equip for Doppler tuning.  But
>it seems to me that the majority of satellite operators do use radios that
>support computer-controlled Doppler tuning, but they just don't use it.
>I find Doppler tuning to be very helpful when operating FO-29.  It greatly
>simplifies the task of "finding" my downlink, especially when I also hear
>harmonics that are coming from my transmitter instead of from the satellite.
>Automatic Doppler tuning is helpful, but not essential, on the FM satellites
>to keep the signal as clear as possible.  On FM satellites it's difficult to
>determine whether or not somebody is using automatic Doppler tuning.  You
>don't hear the pitch drifting like you do on a linear transponder such as
>FO-29.  Sometimes a weak or distorted signal is caused by frequency error,
>but sometimes it is caused by polarization mismatch at the antenna(s).
>When tuning manually, I think the majority of satellite operators tune the
>highest frequency.  But not everybody.
>Wayne Estes W9AE
>Mundelein, IL, USA
>Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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Dr. Jerry R. Pixton, PIXOS Designs LLC

Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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