[amsat-bb] RE: [psk31] PSK31 satellite UPLINK freq?

[Bob Bruninga <bruninga@xxxxxxxx>]

> ...if someone built a 28.X MHz 10m SSB 3 Khz wide uplink receiver no
> larger than half a cigarette pack, I might be able to get it onboard and
> in 6 months we might then have a PSK-31 10m UPLINK => bundled 2m FM
> DOWNLINK transponder...
<snip>

Then, W0FMS suggested recrystaling the WARBLER design for the receiver.

Which then brings up the question of what freq on 10m for PSK-31 uplink.

I have seen 28.12015 recommended as the bottom edge for normal PSK-31
QSO's on 10m.   Do we put the 3 KHz wide UPLINK there or separate it?  Our
potential ride to orbit will be in 6 months on the solar decline... but
there will still be some band openings.

IDEA-1  Put it at 28.120150 to 28.120153 bottom edge of the band.
        This may capture some QSO's not intended for the satellite, but
        it would use a previously suggested PSK-31 freq.

IDEA-2  Put it higher.  But since there is no published upper bound for
        the PSK-31 subband, if we moved it up 3 Khz, then we might later
        end up splitting the band in the middle...

If we get this in orbit, then I could imagine lots of WARBLER type low
cost UPLINK  transmitter kits.  The custom crystals could be bought in
large quantities at drastically reduced prices.  But it would sure commit
us to a FIXED frequency.  With all these XTAL kits, and even after the
satellite fails, then that would establish kind-of a permanent PSK-31
presence in that 3 KHz window.  THus the need for discussion and agreement
on where it would be...

Just dreaming here...

de WB4APR, Bob


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