[TenTec] Triton IV Intermittent Failure

[wes Bolin]

I just put up an antenna for 20M so I can check into the nets and also
chase a
little DX.  As Murphy is alive and well, the 20M band had all kinds of
noise/ pulses/FMing with a S7 to S9 noise level.  BTW today its normal.
And my Triton IV that I had been only listening with decided to attenuate
the receive signals after a
few transmissions.  After sitting awhile, it was normal again. Until
transmitting.

I have a signal generator, and a scope, but wanted to do a quick and easy
problem isolation.  The Cal was attenuated too so I knew the problem was
following the
front end of the receiver.  My technique was to heat circuitry with a hot
air gun from
Harbor Freight and see if I could duplicate the intermittent failure.  Sure
enough the
AGC-IF board was the problem.  I could heat Q6 and the receive signal would
drop.  Spraying a little bit of Cool Spray on the transistor cooled it down
and the
radio worked normally.  I replaced the MPS6514 with a 2N2222A and all is
well.

Alternating heat and cold is a good way to find temperature sensitive
intermittent problems.  Maybe this will help with other troubleshooting
problems.  BTW I love these discrete components.

Wes