Programming handheld to allow for Doppler shift

Anon Anon

Joe - instead of “acquire above” for SO-50, it is the opposite for the new birds with their 2m downlinks.

See the freq chart on the home page at ...



I hope I can ask this question so it makes sense.

Amateur satellites have an uplink and downlink freq.  I have worked AO-50 using my FT60 and an Arrow handheld dual-band Yagi.  The FT60 is programmed to follow the Doppler shift as follows -- I found this programming on the 'net somewhere:

Ch   Uplink freq   Downlink freq

1     145.850     Timer Reset 74.4 Hz
2     145.850     436.805       67 Hz
3     145.850     436.800       67 Hz
4     145.850     436.795       67 Hz
5     145.850     436.790       67 Hz
6     145.850     436.785       67 Hz

I check the N2YO site to see when AO-50 is visible from my location.  I point the antenna slightly above the horizon at time of AOS, rig set on channel 1, and listen for signals.  As the satellite crosses the sky, I try to follow it with the antenna, changing channels on the handheld as the bird reaches zenith then disappears.  The channels are set up as they are to allow for Doppler shift on my transmitted frequency. 

I have not worked AO-50 for a couple of years and now I want to work AO-85, AO-91, and AO-92.

Should I program my handheld for these three satellites similar to the way it's set up for AO-50?  That is:
-- Uplink freq remains the same
-- Program a tone as needed
-- Program the downlink the same was as for AO-50 -- that is, start out above the bird's downlink freq, program a couple of steps to the downlink, then, program a couple of steps below the downlink, all to allow for Doppler as the bird approaches me, then, goes away from me.


Anon Anon

Should have used Google before posting my questions.  Found the answers on K6LCS website -- thanks, Clint.

Programmed my FT60, waiting for the next passes.


Clint Bradford

Naw ... It is just a little different thinking. After years of preaching', "Acquire Above," we get these new birds where that is not true ... (grin)

But those 2M downlinks are incredible! You can hear them with stock ducks on HTs.