[Johnson] Valiant I crystal oscillator won't unkey (solved.. next prob)

[Paul Carreiro, N6EV]

At 12:08 AM 12/17/2008, I wrote:
>I think I may have found the root cause of the problem.  I'm only 
>getting -218 volts of bias on V11 where the schematic indicates 
>-265.  I think I have a soft 6BY5 rectifier.  And as I remember it.. 
>the last time I checked that tube it was questionable.  Heck of a 
>time to have my tube checker out on loan.  Caps have already been 
>replaced in the bias supply so short (excuse the pun) of a bad 
>transformer winding, I think replacing the 6BY5 with a fresh tube 
>will do the trick to increase the bias back up to where it should be 
>(and hopefully cure the crystal oscillator problem).  I just ordered 
>one.. we will see!

Well here's an update on the Valiant work.  I replaced the 6BY5 
rectifier with a NOS tube.  I was right in that the old tube was 
affecting my bias.  Before replacement I was getting -218 Volts 
(where the schematic indicates -265).  After the replacement the bias 
bumped to -244 Volts.  Unfortunately this did not cure the crystal 
oscillator unkey issue as I had hoped.  It did bring the final / 
modulator bias readings back into spec with the current R22 settings.

Next I replaced R11 (33K) with a 100K, and changed R7 (1M) to 500K 
per Darrell, WA5VGO's email.  This solved the crystal unkey problem, 
but affected the VFO negatively, adding a very noticeable 
chirp.  Crystal was a crisp clean signal.  So I switched R7 back to 
1Meg, and added R65 & R66 (both 1 Meg) from each crystal to pin 10 on 
SW2.  That brought the VFO back to crisp tone and kept the crystal 
tone in good shape.  By the way, prior to the above mods, V3 grid 
(R11) had -6.6 unkey volts in crystal position.  After the mod, it 
has -36.5V.  So I think the issue is now solved and I can move on to 
the next problem....

That problem being the VFO Zero function.  There is roughly a 400 Hz 
difference in the VFO frequency in the Zero position, and key down 
(zero is 400Hz higher than key down).  The only difference I see 
between the zero switch position to ground and the key circuit is the 
RF choke at the key input.  Perhaps that's gone bad.  I have a new 
one ready to go in later tonight after dinner.  Any thoughts on this one?

After that is solved.. just need to replace the power cord with a 3 
prong, add a primary fuse and soft starts on the LV and HV xfmrs and 
I'll be ready to perform final alignment and buttoning up.

Working on these old rigs is very therapeutic.  Plus they're much 
easier to work on than the spacecraft at work!  :D

Thanks again for all who provided input.  Any thoughts on the VFO 
zero off freq would also be appreciated.
73 & Merry Christmas to you and yours from  Paul  N6EV