Amen...
> The name of the reflector is Amps. It is about RF linear power
> amplifiers. This is a suitable topic. For those of you who find this
> tedious and boring I think the problem is not with Amps but rather
> with you all needing something else to do with your free time. I
> apologize for not realizing it is All About You, and not really about
> amps.
> K5UJ
Years ago (20) I got into an argument with a respected experienced and seasoned
RF oscillator designer (making dielectric heating machines) of equipment that
was 10 kW and up, in the HF to VHF range. We both debated the arguments about
parasitic oscillations, and it was his opinion that you cannot have one while
the fundamental power was also being developed. It had to reduce the power
there, to support some other mode. The DC power from the plate supply had to be
the same, so where else could it come from? My opinion was that they can be
simultaneous, but what did I know then, i was only about 10 years into the
business and he had many more. Anyway, we never came to a mutually acceptable
agreement that it was one way or the other, and I went off thinking I knew
everything about it. Conservation of energy prevailed.
Why am I bringing this up? Because here we have disagreements that seem to go
for years, with strong minded senior (experience, not age) RF designers or
users. We'll never hear any agreement on the fine details of these magic things
called PS between such strong individuals.
I cannot shout "LET IT REST" because it pops up intermittently every so many
months and years, been happening since this forum started in the 1990s. I think
we should call it a parasitic argument, as it draws fundamental power away from
the fun and incredible knowledge that
this and other on-line experience-sharing allows.
OK, I'll go back under my rock now. Sorry for this digression.
I have about a month left til first turn on of my biggest amplifier project.
The plate blocker capacitor arrived yesterday, weighing in at 250 lbs of copper
and Teflon film, thanks to some wonderful workmanship by Continental
Electronics in Dallas.
Finishing the RTV sealant on the edges of the control grid/screen grid blockers
this morning. Its cathode-driven, grounded grid and screen, tetrode in class B,
VHF. We start testing the plate supply again in a few weeks, 28 kV at 40 Amps
DC, or 200 pulsed.
I do hope that my PARASITIC SUPPRESSOR works, as it costed over $4000 for 10
waveguides plus iron-filled epoxy RF absorber.
73
John
K5PRO
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