The latest edition of "The ARRL Satellite Handbook" contradicts earlier versions, which suggested the same approach that Drew has here (i.e., always Doppler-tune the higher frequency) in favor of "parking" the uplink frequency and Doppler-tuning the downlink (see the section "Finding Yourself ... and Others," which begins on page 5-13 of the handbook). It occurs to me that, in general, that is the worst approach to take - although I admit to only knowing enough about all of this to be more dangerous than not.
Before I added computer-aided Doppler tuning to my station, I took Francesco's approach and always tried to stay at the same downlink frequency, Doppler-tuning the uplink regardless of whether it was the higher frequency. In reality, my approach is only inconsistent with Drew's ONLY on FO-29 because, on AO-7 (when in Mode B) and VO-52 (always in Mode B), the uplink IS the higher frequency. The reason I believe the 2008 edition of "The ARRL Satellite Handbook" offers the worst approach has two elements: 1 - the "slipping" on the downlink that Francesco alludes to in his post, and 2 - the use of VO-52 as the "example satellite" for the description of how to find one's signal. The exercise directs readers to Doppler-tune the lower of the two frequencies to find themselves on the satellite. Later today, I will try the "always tune the higher frequency" rule on FO-29, which I admittedly have not every tried. I'm looking forward to learning how that works for me since the higher frequency on that satelite is the downlink. 73 to all, Tim - N3TL -------------- Original message from Fabiano Moser <fabianomo...@gmail.com>: -------------- > Dear friends, > > We know that some Satellite Operators use diferent system to doppler > control. > > For Linear Transponder > 1) Adjust uplink and downlink automatic by CAT? (Not always woks, some times > I´m up or down from the computer adjust) > 2) Adjust uplink and downlink manual > 3) Keep Uplink fixed and adjust only the Downlink frequency. > > What is the more indicate method to use? > FT-847 have knob to adjust Uplink without change downlink VFO, and I´m using > it to keep my voice in downlink at same downlink much I can. > > But I know some operators use fixed uplink. > > How you do? > > -- > 73 > Fabiano Moser CR7/PY5RX > ARISS-PORTUGAL (Amateur Radio on the International Space Station) > Representative at Teleconference and Portugal Telebridge Coordinator. > AMRAD/AMSAT-CT > http://www.amrad.pt/ariss.php > > "There is no great talent without great will. (Honoré de Balzac)" > _______________________________________________ > Sent via amsat...@amsat.org. 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...@amsat.org. 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
