[SignalOne] [signal-one] Oscillating Q4

[jerry]

So I couldn't resist.  Tired or not, I labelled all the wires, pulled 
the board and took it out to the garage bench.
Tacked SMD .1uF caps across all three electrolytics.  Also added a 
bypass across the existing one on the RT line.  And
one on the 34V line.  Installed the 3KV cap at the output.

Cleaned off the board with electronics spray no-residue cleaner.

Back to the radio.  Whups, broke off one of those little female pins.  
Nothing important - just the output coax to the tube :).  Tacked it back 
on.  I'll do it better later.

It's a little fiddly getting those pins on under the load cap actuating 
rod, but compared to the PA, an utter piece
of cake.

Powered it up and..

First the good news.  The 20MHz crap is gone.  Yay!

Now the bad news.

1.  There is no output.  Plate current doesn't go up with drive.
2.  If you tap on the radio, it goes into transmit - for a moment.  
Maybe my tacked-on cap is shorting the T/R line?
3.  Q4 is not looking very linear.

None of these things are scary.  I'll give it hell tomorrow.

                      - Jerry, KF6VB