Hey Brian...
Many thanks for putting your digital mode thoughts on the reflector.
I was particularly struck by your comment on PSK...I've been working PSK
only for about 6 months now, and was first drawn to it by the "green"
(i.e. low bandwidth, low power) aspects of the mode, but as I have
worked I have been watching that phase scope in the corner and realizing
just how poor this mode is for DX work...the multipath and other
scattering defects spread out the phase information pretty badly (as you
say, "it gets chewed up in the ionosphere). I have never seen anyone
else talk about this problem, tho it is evident enough on long paths. It
is worth mentioning.
Perhaps you can help me identify a mode that I see frequently,
usually just at the upper end of the PSK region, on 20 meters. It looks
on the waterfall like a stream of small rectangular confetti in a band
perhaps 100 Hz wide, with blocks being distributed at random across this
bandwidth fairly densely. It is definitely not a RTTY signal with two
tones, and if one is to guess at the number of tones I would say perhaps
8 or 10 within the 100 Hz "channel" being used. I would send a screen
shot, except there is not anything on at the moment. Again trying to be
descriptive, I imagine this as a stream of punchings from IBM cards, all
aligned with long dimension along the flow of the waterfall...it is
intriguing to watch but I have never been able to decode it to identify
it. I don't believe it is a DSSTV signal. It is clearly a fairly slow
mode wrt data rate.
It would be very useful to the novice digital-mode operator to have
screen snaps of several modes as they appear on the waterfall. I think
that NU8I might be happier with these snaps than with aural samples,
since the waterfall is a very nice time+frequency discriminator. Just a
thought. BTW I use my F3K almost 100% on digital, the remainder being on
CW...
John Ragle -- W1ZI
[email protected]
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