Satgen 414  Amsats Getting Started  by GM4IHJ  (BID SGEN414)  1 Mar 97

A recent packet bulletin contained a classic request for advice from a
man who said " I have decided to get on satellites. I have bought a
multimode multiband transceiver, and a second tranceiver, various
antenna rotators and pre amps. Please advise types of 5XY and 12 XY
antennas , and auto tracking equipment needed "
Clearly the man concerned has no dependant wife/wives/children. But
does he really believe this is the way to start satellite operations? 
The following is a brief description of what he really should have
done. Noting that his present proposals will result in nothing but
grief. Satellite operation is never going to be easy . Surely the only
sensible approach is to start simple.
Before you can make useful satellite qsos, you must learn how to find
satellites (EQX plotter or computer fed with Keplerian elements and
tracking software). Then having found a simple satellite downlink ,
you need to spend several days or weeks learning how to tune in to
other peoples qsos. Keeping this up until you are good at it, and can
handle all the problems presented by antenna tracking, faraday
rotation and doppler shift. All of which you can do using a simple HF
Rx on RS10 ,RS12, RS15 or, using a 2m SSB Rx and simple yagi antenna
on RS12 or Oscar 10s downlinks. Satgen 409 lists the frequencies
When you really can follow a satellite signal from horizon to horizon
you are ready to get a 2m Tx and try accessing the satellite. Even if
you never intend to use morse, it is better to use a key and CW for
your intial tests. Having got the satellite on your receiver , tune to
a section of the passband well clear of other QSOs then, noting the
received frequency, calculate from the uplink to down link conversion
frequency just what Tx frequency you need. Very rough figures are (
subject to equipment calibration and doppler shift) :-

  Satellite      Uplink         Downlink (to get uplink)
    RS 10       145.88          29.38    Eg add 116.5
    RS 12        21.23          29.43 or 145.93 MHz Eg subtract 8.2
    RS 15       145.878         29.38    Eg add 116.498
    Ao 10       435.1 reversed 145.905   Eg subtract from 581.005
Please note that all these figures can change as the orbit progresses,
because doppler shift affects both your uplink to the satellite and
your downlink from the satellite . So in the case of the HF mode A
RS10 and 15 you can get doppler shift of +3 to -3 kHz between start
and finish of a pass. While Oscar 10 mode B has a doppler shift of
about +7 to -7 kHz depending on whether it is approaching you or
receding from you.
So as you gently key your Tx on a clear band . Send one dot and listen
for your return . If you do not hear it tune your transmitter 1 kHz or
so and try again until you find your own signal. Taking care to check
your antenna heading regularly if you are using a beam antenna. Once
you find your signal , switch to USB ( or LSB for Ao10) and put out a
call. Do not try tuning onto others until you have had lots more
practise. In qso just tune Tx to keep your signal steady on your Rx.
Everyone has a different way of starting out. If your Elmer does it
slightly differently, do it his way, so long as you never interfere
with other qsos.