Dear Alberto, LF Group,
Thanks for producing the new version of Jason. Last week I recorded some
.wav files of G4JNT's beacon signal, with and without clipping (although
there will always be some clipping on the biggest noise peaks). I ran an
"unclipped" file through Jason 0.95, using the KK7KA decoder, with and
without the "Hendrixizer" engaged - the attachment shows only a couple of
characters missing with the "Hendrixizer" on, but only garbage when it was
switched off - so it does indeed seem to make a useful improvement.
I got slightly better results when clipping took place in the IF amplifier
- copy was virtually perfect then - so it could be worth experimenting with
user adjustable thresholds or dynamic clipping as has been discussed. I
still have the .wav file if anybody wants it (about 13Mb of it!).
BTW, when watching the decoder in action, "G4JNT" first decoded correctly,
then the decoder retrospectively blanked out the "G" - On the whole, I
think it would be useful if the decoder prints some character even if it
"knows" the character is wrong - perhaps a non- alphanumeric character like
a question mark or just a blank. That way, the operator would know how many
characters had been missed - although it would mean more garbage on the screen.
Cheers, Jim Moritz
73 de M0BMU 
|
