I've got a reasonably stock NCL-2000 (Hi Carl). I'm not looking for more
power, and in fact, given my antenna location on a small lot, I probably
should stay out of 10 meter, at least for any extensive use.
My question is, I've found a source for NOS 8122's not matched, for a bit
over $500/pair. The current ones work, but I'm looking to the future.
My options are:
Gamble on the NOS tubes and hope they're close enough without being
matched? I assume I'd need to let these cook the O2 out for a day or so
before real use. Adding individual bias circuit may be an option, but
raises the cost.
or
Save the money and put it toward a newer mid range PA in that same 1 kw
range (that I can buy spares for today) ($1400-$1700 + spares)
or
Actively work on retubing using something like the 4cx350A's, but
understanding that I'm not a radio engineer, and I'll have to do a lot of
study to make that happen (which I'm not adverse to). looks like the 350's
use half the voltage @ 2x the current for the heater. Plate volts look
right. new sockets from the looks of it. (maybe $350 for tubes plus unknown
for sockets and other parts).
There's also building something up from scratch using power mosfets based on
the reference circuit diagrams, and then coming up with protection circuits
and filtering. Probably beyond my current skill set, but it does interest
me.
thanks for the advice
jim
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