[Elecraft] K3 doesn't work in AFSK-A mode but DATA-A does work. What's broken?

[Don Wilhelm]

You said you have sufficient audio, but please look at the ALC meter and 
tell us whether or not you have 4 bars solid with the 5th flashing 
during transmit.  That is proof of sufficient audio.

Have you tried setting a different tone (say 915Hz) in both MMTTY and 
the K3?

73,
Don W3FPR

On 3/20/2020 10:30 AM, n9ok wrote:
> Bill, I've greatly simplified the setup for troubleshooting. All I have
> running is MMTTY. The radio mode is for sure ASFK A.
> 
> If I simply change the mode to DATA A, all is well.
> 
> This seems to argue again a hardware issue, at least for the keying part of
> the circuit.