[TenTec] HRD and computer control for OMNI VI ver.3

[N4YG]

I would guess that the problem may be with your Serial Port hookup to the 1/8" phone jack. I have never used the serial port (TTL level) connection but rather the DB-25. I use the cheapest Chinese USB-to-Serial converter and connect to my homemade DB-25 to DB-9 adapter configured as shown in chapter 5 of my OMNI VI+ manual. It works great.

Joe, N4YG