Crazy UHF problems.

[taslucas]

Duplex should only be on channels 1 to 8 so that shouldn't have anything to do with it. Sounds like one of them has gone a long way off frequency. I can check them, you just have to come up to here, make sure you bring a flynet.
Screenshot_20231005_180359_Maps.jpg

I'd love a trip but it might be a bit more cost effective to get one of those icom ic-455 you've mentioned.....

.......from under the great down under.