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PSK-31 Transponder notes.



Operation on a PSK-31 3 KHz satellite transponder is going to be totally
new and nothing like you have ever seen before.  Let me explain this since
there has been some criticism of dedicating the transponder to only PSK:

1) SOftware exists that can display a horizontal waterfall and 20
simultaneous QSO's.

2) The satellite is full duplex, so you (and everyone else) can be
Transmitting 100% during the full 15 minute pass.

3) Thus instead of 1-to-1 half duplex TX/RX you end up with a GROUP event
with everyone talking to everyone simultaneously.

Not as in a bedlam of gyberish, but in the sense that as fast as you can
type,  you can be commenting to anyone or everyone in the group at any
time.  That is the ultimate in a low cost multi-user satellite.

You cannot do this on voice on a wideband transponder.  THe human brain
cannot pay attention to 20 conversations.  But with our lap-tops, and
multi-user PSK-31, we can.  Thus, this satellite design is meant to take
advantage of that opportyunity and to maximize the fun for everyone.  And
since it was going to be a 2m FM downilnk, anyone with an HT can receive
it.

I just thought I would add this note, because it may not be apparent how
radical this transponder can be.

de WB4APR, Bob


And since it is FM on the downlink, all the Doppler correction is done by
the software on the uplink (since each trasnmitting station can see his
OWN signal and closed-loop, keep it where it is suppposed to be in the
non-doppler downlink.  If I say "ill be on 1250 Hz" then that is where I
will be throughout the pass.


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