To: Users and Potential users of JT9 and WSJT-X
From: Joe Taylor, K1JT
Many thanks to all those who have sent *.wav files of JT9 signals, as
well as comments on early release(s) of the WSJT-X program. They are
much appreciated -- and much has been learned from them, already.
I'm well aware that the already-released code has some inevitable rough
spots. The main goal of these early releases was to obtain some
on-the-air experience, and in particular some recordings that would help
me to evaluate potential issues of phase and frequency stability,
atmospheric noise, local QRM/QRN issues, and so on. These efforts have
already been successful -- and more of the same will still help.
The most useful files are those obtained with signals near the decoding
threshold. The signal should be weak but visible on the waterfall when
running in the appropriate JT9 submode. Maybe it decoded, maybe it
didn't. Some of those that didn't decode almost certainly will, after I
optimize the decoder by including corrections for small frequency
drifts, effective noise blanking, perhaps "birdie" elimination,
averaging over successive Rx sequences, etc. At this stage, recordings
made in the faster submodes (JT9-1 and JT9-2) are as useful as the
slower ones -- and they are less frustrating to work with, since you
don't have to wait so long to see if things are working.
As mentioned in an email several days ago, I am nusy with other
obligations for the next week. After November 12 I can once again
devote some effort toward these WSJT-X goals.
With best wishes to all,
-- 73, Joe, K1JT
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