Ron,

None of that makes sense to me . Pin 1 (cathode) of the 6AL5 would
be a modest DC level that varies with speech level and actuates the VOX
relay tube. And 33pf is too small to couple anything but a very sharp
transit spike from the junction of C42 and R77 as the rig switches to
standby.

I would remove those added components.

My factory wired 20A that I acquired (used, of course) in 1964 is still
my main station exciter and has no modifications whatsoever. I had to
replace R45 several years ago as it's value creeped up and I really had
to holler in the mic to get the VOX relay to pull in.

John