>If your plate choke were absorbing even 100W I believe it would quickly
>become hot enough to smoke. Another possibility - maybe - a choke impedance
>consisting of a low value of effective series reactance and also relatively
>low effective series resistance (i.e., near a high Q series resonance?) at
>your op freq could CONCEIVABLY make it impossible to tune the tank close
>enough to get significant output.
Well, if run long enough it will smoke. However, if Alek has just been
making quick measurements and not running the power for that long, then
no, you might not smoke it.
When my choke was resonant at 29 MHz, I ran quite a bit of 28.3 MHz power
into it before it went bang.
>
>This is pure speculation; I don't recall having seen such a situation,
>where the choke screwed up tuning but didn't overheat. But it seems
>conceivable. Ian? Tom? John? Carl? Anybody experienced this?
Don't know.
But speaking of chokes and choke impedances, here is a question that
another member of the reflector posed to me a week or so ago. Maybe
someone can answer it:
The average output impedance of the tube is about 2 to 3 KOhm. From my
RF knowledge, the tank circuit when tuned, looks like approximately the
same impedance. However, a typical RF choke at 80 m has an impedance
around 2 KOhms or so. This is right in the ballpark of the impedance of
the tube, it's not a "high" impedance relative to the tube's output.
So...why does the choke work???
Am I missing something?
73,
Jon
KE9NA
-------------------------------------
Jon Ogden
KE9NA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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