[RTTY] [MMTTY] The Problem with AFSK ...

[Salvatore Irato]

I would not enter in the measuring arena, not being in a lab a lot of
time ago. But What I had seen is maybe quite the same. It happened
just during the last WPX. I was SOSB on 40m. At a time I had a
northern caller on my rig, no more than 800 Hz. I discerned quite
clearli his signal CQing not even going reverse. On my P3 the signal
was much more lower quite at the noise level. I was able to decode
him, that was from my north BTW.
I don't have any clue if he was going AFSK or (too badly) with FSK.
But my personal opinion would be AFSK.
His main signal, with a 2 el. on 40m aimed quite into his direction,
go imaging. But the harmonics was almost under S1 on my scale. It was
daytime end on 40m.
I managed to stay there as several calls kept incoming without any
apparent problem for that time on 40m. Anyway all the band was crowded
like a egg. The rate seemed to me appropriate for that time. My filter
was 500&400 Hz.

If I remember right ...
The main signal was somewhat up from my QRG, 800/1000 Hz.
I was anyway out of his bell carved signal.
I decoded him without reversing. Would this have sense? Any clue about?

BTW With a K3, I will stick on FSK.

   73 de iw1ayd Salvo

PS time to time in bands there are really terrible signals, even from
the more conscious AFSK operators, it may happen that something is
forgotten on time. Not so with FSK, where out of bad commercial
transceivers there are not too much added variables on our hands to
make something wrong.