I purchased my Ten Tec Corsair II from an estate sale several
years ago. When I first got it, I noticed that it would only
produce about 75 watts, and didn't mess around with it for
awhile. Well, time passed, and I bought a Centurion amp. So,
in order to get the amp to produce the correct output level, I
went inside the Corsair, and found a spot where a resistor had
burned (while in custody of it's previous owner) and replaced
(also by previous owner) on the ALC board. The circuit traces
were burned leading to the resistor, so I can only assume it was
some sort of catastrophic failure. The rest of the rig looked OK
on inspection. I followed the instructions in the owners manual
and adjusted the ALC control pot inside the radio, and brought
the power level back up to 100 watts out (according to -my-
meter in my Ten Tec 238 tuner). This was difficult because the
power supply circuit breaker kept tripping. But I finally got it
done.
Everything worked quite well for awhile, then all of a sudden I
started getting complaints about RF on my signal. The ALC
light -just- lights (setting DRIVE per Ten Tec's instructions)
when the control reaches about 12 o'clock. When I reduced
the DRIVE control to about 9 o'clock, the problem seems to
(for the most part) go away. I could hear myself in the power
supply speaker as well, though not very intelligible.
I connected a ground braid from my ground system to the
gooseneck on my Ten Tec 705 mic, and it sounded like a
motorboat in the shack with RF coming out of my power
supply speaker! The RF out meter on the rig pegged to the
right also. I then noticed that I had failed to connect a ground
to the set itself, so I did this.
I now notice that the microphone is "hypersensitive" when
DRIVE is adjusted properly. And audio reports state I sound
like H-E-double hockey sticks. That is unless I mis-adjust the
DRIVE to 9 o'clock. Even then listeners state they hear a
slight problem that sounds like RF on my signal. I went inside
the mic, and verified all ground connections there as well, and
did seem to get a better ground per my ohm meter after
doing some connection cleaning. (Checking between the radio
mic connector and the gooseneck). I'm going to check that I
have a ground on the power supply this morning, but I have
doubts that this is the cure, it almost HAS to be something
inside the set (a missing/open bypass cap?).
Any ideas on where to look?
Thanks, -Web in Myrtle Beach, SC
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