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

[Jim Brown]

On 3/21/2020 12:50 PM, n9ok wrote:
>   I don't know what about the installation was incorrect. It
> could well have been something intermittent in the K3. Or some silly
> misconfiguration on my part. I hope it was an MMTTY configuration issue but
> only time will tell.

There are "gotchas" buried in MMTTY .ini files that can bite us if we 
use low- or mid-frequency audio tones. They assume that you use the 
default high tones, so if you do, there's no problem. But if you use low 
tones, as I do because they make it easier for my ear-brain to tune in 
RTTY signals, the two .ini files in the MMTTY directory must be edited 
to define the low or mid tones you've chosen. MMTTY.ini defines general 
setup, while USERPARA.ini defines all of the optional decoding 
algorithms, like "Fluttered Signals," "Multi-path," and so on.  If 
you're using low or mid tones and these files are not edited, every time 
you change the decoding algorithm you'll be reset to high tones. (I 
learned this the hard way.) :)

This is the line that must be changed to whichever tone you have chosen. 
It occurs multiple times in both MMTTY.ini and USERPARA.ini 
DefMarkFreq=2.125000e+03

Scientific notation is used to define the frequency -- 2.125 x 10e3 Hz 
-- 10e3 means x1,000, so 2,125 Hz.

These files must be edited with a plain text editor (Notepad on a 
Windoze machine) and saved in the same directory and with the same 
filename and extension.

FWIW, I'm using 2Tone as my primary RTTY software, because it can select 
between left and right channels for both RX and TX. MMTTY can select 
between left and right for RX, but not for TX (that is, it sends to both 
L and R). I do this because I do SO2R contesting, running both radios 
from the same computer. I use MMTTY for second decode windows on both 
radios. 2Tone, by a ham in the UK, has many advantages, including 
improved decoding and carefully shaped keying for minimum distortion. 
GRITTY is by VE3NEA, who wrote Skimmers for both CW and RTTY. I haven't 
tried it yet.

73, Jim K9YC