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Re: Failed attempt on FO-29.



Hi Pat,

Maybe the following is valid for more sats (eg AO7) and to all new to using 
them:

What I would recomment is listening first for a few passes, just to get a 
feel for it.
Next I would go for CW:

1. Tune your receiver to a free downlink frequency and keep it at that 
frequency, eg 435.850 MHz.
2. Now put a (CW) signal at 145.950 MHz and see if you can hear yourself on 
the downlink.
    Easiest to find out the doppler shift is by simply tuning the transmit 
frequency up/down a bit
    (a few KHz) until you hear your own signal
3  During the pass you keep the RX frequency constant, and you tune / adjust 
the TX frequency

Actually, doing this is great fun !
You hear yourself back over the satellite, and doing so in CW is 1000x 
easier as using SSB.
Also you get a good feeling for what happens during a pass, not only for 
doppler, but also for other aspects
like how much power is needed (for CW I'd say 10W and a simple beam).

Only after you have done this successfully I would go for the next step: SSB 
contacts (again: first with yourself).

At my web site I have some example audio samples of satellite contacts I 
made: http://www.qsl.net/pa3guo,
click on "contacts", on the submenu click AO7 for such a CW experiment (Mode 
A). FO29 has less
distortion and sounds are much clearer.

Of course: for this you need to be able to hear yourself while transmitting, 
that is a hard requirement for FO29.
If you are using an FT-897, you need two of them I guess (one to TX, one to 
RX). But of course any combination
of transceivers would do, you could for example also use an FT817 for 
receiving. Tranceivers like the FT-847,
ICOM910 or Kenwood TS2000 with SAT modes can receive while transmit, of 
those you need only one.

This does not take away that doing CW on FO29 is actually most fun: you do 
not need anyone else (just listen
to your own downlink), and simple antennas will do.

Henk - PA3GUO
http://www.qsl.net/pa3guo



Hi All,

  Erik KB9BNY and myself were trying FO-29 this morning on the 1548Z
pass.  We heard K7MT, W7JPI and others but since we were completely
manual in operation. It was really confusing to calculate TX and RX
frequencies and keep track of doppler as well.  We may try this again
tomorrow morning if the weather is permitting.  We were running an
Arrow with an FT-897 running 5 watts.  Sorry if we came across
someone's QSO.  Better luck next time.

Is there a table where someone has laid out the TX/RX conversions with 
doppler?

73 de Pat --- KA9SCF.
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