[Amps] Follow-up on "talking" 3KA choke, other notes

[Jim Barber]

The "talking" or "chattering" 3KA choke issue is resolved.

Believe it or not, what fixed it was one of the following:

(1) Replacing the original carbon comp resistors in the parasitic 
suppressors with new Ohmite OY from Mouser

(2) Replacing the tubes. I ordered a new "matched" set of 
Matchlett-branded Chinese 3-500ZG's from K5SVC and installed them. 
(initial quality and performance are both excellent)

Since I didn't test between the two events I can't tell which was the 
"fix", but if I had to bet it would be on the tubes.

Other notes and wonders:
ZSAC is 180ma @ 3800V, (4KV unloaded) which would appear to be normal 
for +10V bias. After 30 seconds or so of idling with no drive, though, 
the plate structures glow a medium orange that extends from the bottom 
to approximately one third up. 1500W PEP SSB ("four, four, four") or 
continuous dits at 45WPM cause the glow to creep up to roughly half the 
plate structure after another minute or so. A two-minute full power AM 
transmission (375W carrier, 1500W PEP) extends the medium-orange glow to 
roughly two thirds of the structure, with the bottom part now glowing a 
brighter orange. (tank is loaded for 1500W) Ep doesn't drop much below 
3800V - the supply is quite stiff.

So after that laborious description - does that sound right for these 
new-fangled graphite plate tubes? This is my first experience with them. 
If memory serves, the old Eimacs didn't show as *much* color at legal 
limit levels.

Thanks,
Jim, N7CXI