When I tune the radio to myself and hit "t" I get a beep, then there's a slight delay, and then I hear what I just said through the speakers.
If I tune to someone else within range it doesn't work and I don't hear my voice through the speakers. If I'm looking at the radio box, the "T" is lit up when I push the key in both cases.
When I hit the F12 button that lights up too, but there's not beep and apparently no voice goes out.
I dont' know if this is a factor but the V radio changes tunings, sometimes its 4 squad when I log on and sometimes it's 101. If I've just tuned my radio it will read both 4 squad and divide, for example.