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Re: TNCs for 1200bps PACSATS



Tate wrote:

> Now - where can I find more info on BPSK so I'll have a clue what I'm looking
> for.

There's not much out there. If it doesn't say BPSK, it isn't BPSK.

The terrestrial AFSK (Audio Frequency Shift Keying) sends bits by
using two different audio tones. BPSK (Binary Phase Shift Keying)
flips the carrier phase through 180 degrees to send information.
The modulation formats are completely incompatible...

I've only heard of one soundcard implementation for 1200 baud PSK
(Hi Doug!). I'm not sure why the lack of interest - while 1200 baud
doesn't sound like much (it isn't), when AO-16 was on the air it was
the perfect satellite for email and general chitchat. Maybe it's the
peculiar (but somewhat logical) uplink setup. I dunno. I played with
digipeating stuff off LO-19 and IO-26 while I was at school. That
worked well too, but I never saw anything else other than a handful
of APRS packets.

This stuff is not covered at all well in the amateur press - Tom
McDermott's book (published by TAPR) tries, but digital communications
is a huge area, and in 150-odd pages you can only just barely hint at
scratching the surface. The satellite protocols are another matter
entirely, and other than the original documents very little has
been written about them.

Ham radio seems to have a real problem with all things digital.
This is a shame.
-- 
Laura Halliday VA3LDH    "Laisse le vent tout emporter..."
Grid: FN03gs                - Foly/Viennet
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