Re: LF: Fwd: JT9-2 failed now JT9-1 500khz + 1400hz

[Joe Taylor <joe@Princeton.EDU>]

Hi Eddie, Tobias, and all,

I've solved the riddle of Eddie's local JT9-2 transmissions that failed 
to decode.
The problem is, as originally suspected, the result of small frequency 
drifts -- in this case acting together with the Gray-coding applied to 
the data.
I will work on a solution this week, including an appropriate algorithm 
for measuring and removing small amounts of frequency drift as part of 
the decoding process.
In the meantime, if you're experiencing this problem it's best to stick 
with JT9-1 because that sub-mode has the largest tone spacing.
        -- 73, Joe, K1JT