[Drake] TR-6 Alignment

[wabate]

Six has been pretty quiet so I decided it was time to check alignment on 
my TR-6.  It was last done about 6 years ago.  Everything was going 
pretty well on receive.  Just a touch here and there.  Then I came to 
the 57.75 trap alignment.  Wish I never touched the d__n thing!  I was 
able to reduce the image more but then I noticed I had birdies up and 
down the dial.  I kept adjusting R-207 and C-120 but it only got worse. 
  At one point I could not hear the calibrate signal!

I got the GDO out and set the trap with that.  Then I slowly adjusted 
both controls until I got the receiver back.  All total, I must have 
spent 2 hours with that trap.  I have one loud birdie at 50.00 +/- but I 
can live with that.

The question is what is causing this critical adjustment and 
oscillations?  I am ready to blame Q13, MPF102, the first mixer.  Anyone 
have a similar experience?  I don't want to be a parts replacer but I 
can't seem to narrow it down any better or come up with a better 
explanation.  Is this the nature of the beast?

Thanks,

Bill, K3PGB