On 12/8/2023 1:10 PM, mike repinski via
groups.io wrote:
Did the caps short and put
high voltage on the antenna causing the amp meter to peg? Is
there a rf choke at the output connector?
As in any quality-designed-and-built power amplifier, yes, there
is a good-sized, large inductor from the output of the pi-network
to ground to guard against exactly this kind of failure mode.
What seems particularly impressive, in this case, is the fact
that when those caps arced over, they did not cause a BIG BANG, as
most of us might have expected. I never heard anything (but then
again, I don't hear much other than CW, anyway). Instead, the HV
simply rapidly drained off and the amplifier shut down (except for
the afore-mentioned logic power supply, which apparently kept the
front panel LEDs lit up although they never indicated what was
going on, let alone that a fault had just occurred).
This experience makes me hopeful that when the day comes that one
of the 4CX1000s flashes over (if ever), the amp will shut down
gracefully just like that instead of announcing the failure by
emulating a shotgun going off in my ear? 8-D? I've had my share of
those but no, that's not why I'm so deaf.
73,
Steve K0XP
