________________________________________
Van:
[email protected] <
[email protected]> namens Eric NO3M <
[email protected]>
Verzonden: maandag 12 november 2018 21:42
Aan:
[email protected]
Onderwerp: Re: LF: SlowJT9 v0.9.02
Paul, et.al.
Correct, the original timings were fit into a "window" vs. simple
scaling. Since the slowJT exe wouldn't run in WINE, I just ran a few
commands to decode K5DNL:
arecord -c 1 -r 12000 -f S16_LE capture.wav
sox capture.wav capture_tmp.wav speed 2.0
jt9 -9 -d 3 -S 300 capture_tmp.wav
cat decoded.txt
decoded.txt:
0000 1 -26 0.1 2400. 1 VVV DE K5DNL JT9
jt9 is the standard executable decoder from WSJTX v1.9.1.
73 Eric NO3M
On 11/12/18 3:12 PM, N1BUG wrote:
> Eric brings up a good point. Forget what I said the other day about
> beaconing with a U3S to be received by SlowJT9. I believe that won't
> work because the U3S uses the original JT9-2, -5, -10, -30 symbol
> lengths which are different.
>
> Probably (a guess) in the original, symbol lengths were chosen to
> fill as much of the period as possible while leaving enough time at
> the end for decoding. I would further guess there were specific
> decoders for each submode, or one decoder whose parameters could be
> modified for the current submode.
>
> 73,
> Paul N1BUG
>
>
> On 11/12/18 2:47 PM, Rik Strobbe wrote:
>> Hello Eric,
>>
>>
>> yes, a scale factor of 2 and 5 is used.
>>
>> I hadn't any information about the old JT9-2 and JT9-5 modes and
>> those scale factors seemed the most straightforward to me and
>> make the conversion to JT9 easy.
>>
>>
>> 73, Rik ON7YD - OR7T
>>
>>
>>
>>
