[TenTec] Omni VI with MMTTY problem

[Jim]

I have been successfully using my Omni VI Opt 3 on FSK with MMTTY for a 
few years now. I recently have developed a problem.

To call a station, I align the yellow lines on the MMTTY FFT display on 
the mark and space of the received signal and hit the TX button. 
Recently, when I do this, my transmitted signal is 300-400 hz away from 
the received signal. One station mentioned it to me, and others have 
responded by changing their frequencies to my transmit frequency. This 
creates a fun exercise as we chase each other around the band. Any ideas 
what could be causing this?

I have a problem that may be related. In one of the filter positions I 
have the 500 hz RTTY filter (#216 I think). For the past few months, the 
passband of the filter has been skewed to the side of the two yellow 
lines of the FFT display, making the filter unusable except on the 
strongest signals. Could this be a related problem?

I haven't called TT on this yet, since there are people on this 
reflector who know more than some of the TT technicians. Thanks!

			Jim  N4AL
			n4al at arrl.net