Learned gentlemen...
Excuse me if this is somewhat off-topic, but I've been following the
811 amp discussion with much interest and have a related question:
I'm currently doing some work my pair of 813's and was thinking about
the 'parasitic' problem as discussed on this list.
My fear is not blowing the tubes or the band switch, but rather in
blowing the front end of a modern transceiver driving it. The
configuration is a pair of 813's truly running zero bias GG (grids all
tied together and connected directly to ground ~ 50 ma. idle current
at 2200v). No band switch (rotary inductor pi-network). Manual
switching tx/rx avoids hot switching. Input to the amp is grounded in
Rx. Works 80 thru 20 only.
Should I be worried about the parasitic problem taking out what's
driving it? If so, how to prevent (minimize) that? In the 40 years
I've been running this beast (still the same set of tubes) I've driven
it with everything from a Viking Ranger, to a Jupiter and never had so
much as burp. But one never knows.
Getting nervous in Vancouver,
va7vv
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