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Re: re:Linear Trasnponders



On Mon, 21 Apr 2003, Edward R. Cole wrote:

> PSK-31 sub-band on 20m occupies about 2 KHz  14.070 +/- 1 KHz and I have
> seen a dozen concurrent QSO's in progress.  On satellite it might be more
> difficult due to doppler.

Not really with our design for PCSAT2.  The downlink is FM so the only
Doppler is on each person's individual UPLINK.  But since he can see
himself in the same (non-Dopplerized) waterfall on the downlink, then he
can make sure he stays where he intends to be.  So does everyone else, and
thus if you wanna be on 1100 Hz, then you just keep yourself there.

Also, Peter Matrtinez has developed code that will automatically adjust
the uplink to give a near constant donwlink on this kind of one way
doppler system.  Back when we were designing this thing it was his
suggestion to use FM on the dowlink in this fashion.

Operations will be unlike any other PSK-31.  Because EVERYONE will be
operating FULL DUPLEX.  Thus you can be transmitting while watching what
the other 20 people are saying.  Think of it as a BIG 20 person CHAT
room..

Bob, WB4APR



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