RE: [wsjtgroup] Loading a WAV file into WSJT V9.02
Decodes okay for me too Pete
18 -6 0.8 0 3 * G3LTF DL9KR JO40 1 0
Your file decodes perfectly with WSJT9 here:
sample 20 -4 -1.2 0 3 * G3LTF DL9KR JO40 1 0
Could it be that you have entered something other than 1.0 for Setup ==>
Options ==> Rate In? Your file was presumably generated with the correct
rate; but perhaps you normally receive with a soundcard that requires
1.0068, or some such number?
-- 73, Joe, K1JT
On 3/15/2012 7:55 PM, el_supremo01 wrote:
> Hi All,
> I have written a program (which includes code from 7l1rll) to generate a windows WAV file containing a JT65A transmission. The file has a standard WAV header for signed 16-bit mono, sampled at 11025Hz. The code symbols produced by the program agree with the sample output from the original code by 7l1rll. The audio files I've generated from the program sound to me exactly the same as test files recorded from the output of WSJT. Comparing them on the spectrum display in GoldWave shows that they are changing tones at the same time.
> BUT, when I load one of my files into WSJT it doesn't decode anything. Maybe not too surprising perhaps, but it now gets weird. If my WAV file is played on the computer and WSJT listens to the audio, it does decode the signal perfectly. I can't get my WIN7 system to copy what is being "sent" by an audio program but I'm working with Doug VE5UF on this and he says that:
>> That new file will not decode when loaded into WSJT. But if I let it "play"
>> in the sound editor app, and let WSJT "listen" to it in monitor mode with
>> the start-of-play beginning at the start of a WSJT minute period, it
>> decodes perfectly.
> and he also found that:
>> I also made a CQ from DL9KR [using WSJT] and it also works when played,
>> but similarly will not decode when loaded:
>> 213100 17 -3 -0.6 0 3 * CQ DL9KR JO40 1 0
> I can't figure out why WSJT9 can decode the various example audio files directly but it can't read the ones I generate and it would appear that it can't even read (some of the?) files that it generates either.
> Any ideas?
> I've uploaded one of my files (it's 1MB). It encodes the message "G3LTF DL9KR JO40":
> Pete VE5VA
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- Hi Pete,
I think the mystery is solved. Your test file decodes in WSJT9 if and
only if you have checked "Quick decode" on the Decode ==> JT65 sub-menu.
Although JT65A has become popular on HF, the JT65 modes were designed
for EME, where there is a 2.5 s propagation delay. In normal operation
decoding starts at about t=52 s into the Rx minute, and the decoder
looks for proper synchronization from about DT = -1 s to +5 s.
The "Quick decode" option was added with terrestrial use in mind. With
that option checked, decoding starte at t=48 s and the searched DT range
is shifted a bit earlier.
Your test file probably has the signal starting at t=0, right? Anywway,
the decoder finds it at t=-1.2 s, just outside the acceptable range
*unless* "Quick decode" is checked.
-- 73, Joe, K1JT
- : I've uploaded one of my files (it's 1MB). It encodes the message "G3LTF
Sounds like an old radiosonde.