[RTTY] MMTTY, permanently disable AFC

[Tim Shoppa]

G3YYD wrote:
> With AFSK, when S&P you copy a call and you hit enter to call him. No need
> to worry about tuning him precisely so you call him on his frequency as
the
> software has done it for you. With FSK you either wait for him to
transmit again
> to tune him in or you call off frequency with a lower probability of
success.

I think you work your VFO knob differently than I do. My ears and the
computer are set to standard 2125Hz frequency. Tuning aids like the
waterfall and especially the MMTTY X-Y scope are incredibly useful with AFC
off, I can tell from the tilt of the X-Y exactly what fractional revolution
I have to turn the VFO knob. Tuning in to last partial letters of a call
and completing the Q in a sprint, tuning is simply not a problem.

All the above is true, until AFC accidentally gets turned on. Next thing I
know I am hearing the right tones but seeing nothing on the X-Y scope.
MMTTY has wandered off into hyperspace and it has decided to "correct"
center frequency, way out of my receiver's passband. I will see if some of
the suggestions offered here make it usable, plan to try them in Thursday
night sprint.

I find MMTTY AFC to be very counterproductive to tuning in a RTTY signal
"right". MMTTY decides to start wandering the center frequency and next
thing I know the X-Y scope is no longer centered on standard 2125Hz but is
hundreds of Hz off, and all the coordination between my eyes, ears, and
fingers on the VFO knob goes right out the window. This is very
disconcerting. 2Tone's "rubber band" AFC and waterfall always showing pips
for the ideal frequency, seems a little closer to how I work.

Tim N3QE