[TenTec] Using Omni VI+ woth MMTTY on FSK - final report

[Jim]

Thanks to help I received on the Ten Tec reflector and on the Yahoo 
MMTTY Group, I now have my Omni VI+ working properly on FSK using MMTTY.

It seems that the interface circuits suggested by AA5AU, K4ABT, and 
others, work on RTTY with the Omni V/VI but reverse the signal. I 
bypassed the transistors in the interface circuits with a 10K resistor. 
This feeds the DB-9 pin 3 FSK signal from MMTTY directly into the 
Mark/Space jack on the Omni VI. (On the Omni V this jack is labeled RTTY 
KEY.) It works like a champ.

Another option is to add a second transistor, resulting in a two-stage 
interface. One very helpful peron reported using this successfully with 
a Rigblaster.

The Rascal interface sold by Buck K4ABT does not work as he sells it. I 
had to modify his Omni VI cable by adding an FSK line. I also had to 
bypass the FET in the Rascal's FSK interface with a 10K resistor. Now, 
unlike the AA5AU circuit, it provides not only an FSK signal but an 
audio signal for PSK31. Buck's email responses to me sounded like he is 
not familiar with the Omni V/VI. (His interface and cables worked fine 
on AFSK.)

Thanks for all the help. Listen for me this weekend on the CQWW RTTY 
contest.

				Jim  N4AL