[Kenwood] FW: TS-830s Unstable drive

[Jim]

From: Jim Barrie <barriej@cinci.rr.com>
Date: Sat, 03 Jan 2004 17:41:16 -0500
To: <kenwood@mailman.qth.net>
Subject: TS-830s  Unstable drive

Hi this is my first time posting to this list.
Have a TS-830s and it has worked great for the last two years. Recently, I
noticed that when I try to tune the drive, it has become very unstable. With
the meter in ALC, the drive varies up and down. Also notice the bias is also
unstable, moving around +/- a volt or two.  I changed out the 12BY7A. twice.
The second time in,  I noticed that the previous owner had replaced R36, a 2
Watt, 39K resistor with a 100K resistor. Also, R37 is rather dark in color,
but not sure if it came that way or not.
I also cleaned the band switch with a small amount of Deoxit.

The finals seen to tune ok, and I see no decrease in output.

Any suggestions?
Also, what's with the piece of copper next to the 12BY7A ? Find no reference
to it in the manual.
thanks,
Jim
WA8SDF