[Drake] TR4C weird xmit trouble

[Dick KF4NS]

Ok guys, I have this black cloud over me right now. The radio is 
receiving fine (other than the filter defect) and I decided to get the 
xmit completely checked out before I wrap it up.

All of a sudden while on 20M band position and checking the PS bias, 
it jumps intermittently to 400-600ma with no drive, sideband switch in 
ccw position (actually  makes no difference), dummy load connected and 
no mic or key connected.

After quite a few hours pulling out my hair (just the gray ones) I 
tweaked the TUNE control and the trouble went away. I tried full ccw 
and cw and everything  in-between on all the other bands and no 
effect, only affects 20M and only when the TUNE control is between 1 
and 6. I checked and rechecked the band switch contacts over and over. 
What the heck, I even tapped all the tubes and every other silly 
thing. Given time and a few cups of coffee I can usually make sense of 
these kind of things but not this time. HELLLLLP!!

73, Dick KF4NS
St Petersburg, FL 33714 USA
Keep The Glow!