[Johnson] Viking Thunderbolt

[Steve H]

Well, I think I am finally out of the woods with this project, after 2 yrs 
of patience, and TONS of help
from other owners of this amp - hats off to them too.

I can get about 1KW with a CW carrier into a dummy load so far with my 
tests...so am pleased.
All is stable, no smoke, sparks or strange noises.

I am still babying it for now, and made a few contacts on 40m with good 
reports on my signal.
I creeped up the input RF so I was about 700W average on the power meter in 
LSB, and after some
sort of long transmissions, can see the tubes starting to glow a comfortable 
RED on the plates, which mean
they are happy.

One thing puzzling some is the fact that when I key up at idle with no RF 
signal - plate current meter reads zero,
or is so low the panel meter cant register it. AB1 config is suppose to 
reduce idle current from the normal 350mA
or so the amp usually draws in the factory AB2 mode, but since I have 
changed the main bias tube to a 105V one,
I suspect I am sort of closer to class C a little, and thats why. The 
original config used a 75V tube as the bias, and
I remember it was giving me about 100mA at idle with no RF input.

Completely gone, is the mild plate current draw at idle in TUNE mode. I was 
curious about that, and other owners of the stock amp seem to
say theirs does that as well.

--
Steve Hearns [ KA2PTE ]