"Once it drops below 7.6V I can't transmit. This just seems rather odd, "
?
I don't think that is normal.? Under load, you really can't expect 6x NiMH to maintain over 7V.
My problem is that no matter the watts, I have to shout to get much modulation (it's me...).? One of these days I'll buy the speaker/mic.
radellaf