Quote:
Originally Posted by kj4mqa yes the swr or 1.2
the prob was worse before i put the fan on it.
it also sounds like a fan running in the back ground even with
the mike gain off??
thanks for the help. 73 kj4mqa |
My voltmeter has temp sensing function; if you don't have one that does - borrow one if you can. Something in the output circuit is obviously getting too hot. Maybe a bias resistor - or a final.
Sounds like a part is becoming 'microphonic', could be a resistor. Tap a few of the parts around the output circuit -very gently- when keyed, until one is found that is excessively noisy. Bingo. Be discerning and careful when tapping; otherwise you may pick the wrong part.
'Care' - is the keyword...
BTW-Is there enough heat sink thermal grease between the final and the heatsink? Re-apply a dab - and be sure.