[TenTec] Omni VII: Need Help with a Strange Problem

[David and Dianne on Comcast]

Hi All,

My 18 month old Omni VII has recently developed a 'funny' after performing flawlessly since purchased. 

This rig has the ATU which was installed at the factory.

When first starting the radio cold, whether connected to my usual antenna, other back-up antennas or a dummy load, upon activating the ATU, the rig will inject terrible feedback into the speakers and/or headphones that consists of a cross between a 60 cycle AC hum and RF feedback. It's really bad. 

The ATU hunts for a match but fails and the receiver seems somewhat de-sensed when it switches back to receive from the tune cycle.

then... 

After the radio has warmed up for 15-20 minutes it operates as normal with no sign of this condition throughout the remainder of its use during the current session.  Once cold, it repeats again.

A conversation with Gary at TT Service suggested that I first do a master reset, which I have not done yet deciding instead to see if anyone else has had a similar experience or can offer any alternative suggestion.

My suspicion is an ATU component or SWR detecting circuit component that is nearing a failure??

I'm trying to first avoid clearing my settings via a reset or ultimately having to send it back to TT, which may have to be done in the end.

Open to any suggestions that can be offered.

Thanks in advance,

73 de N1LQ-Dave