On Wed, 26 Nov 97 16:16:26 -0800 Rich Measures <measures@vc.net> writes:
Lots of SNIPS...not worth repeating
>>I did tell you very clearly that the 220 had a problem with VLF
>>parasitics ...snip...
>
>Indeed you did mention this scenario. However, it didn't wash because
>
>there is no VLF resonant circuit in the anode, and the 50uH HV-RFC has
>
>rather low reactance at VLF.. IMO, the VLF issue looks like yet
>another
>rauchian smokescreen.
So why dont one of you guys prove that one way or another. Set up a
SB-220 at a neutral location and have at it. Just stop the bull shit
here.
>>> If your amplifier arced mysteriously, it might be interesting to
>measure
>>> the resistance of the VHF parasitic suppressor resistor.
>>
>>Heat any carbon comp resistor to 150-200 degrees C for years and
>>measure it. Carbon composition resistors change value from long term
>>temperature exposure, anyone in electronics for a period of time
>>should know that much.
>>
>True enough, Mr. Rauch, however the suppressor resistors that were
>being
>promptly damaged in my amplifier were essentially shorted out by
>several
>inches of #16-gauge copper bus-wire - - and the fatal damage was
>happening during operation at 7.25MHz.
>
>>It's pretty darned hot up at the anode connectors. That's why the
>>resistors change.
>
>There is a gale of fresh cooling air at that spot in the SB-220. The
>changes were typically taking place in less than a minute. .
>
>>It matters not what the heat is from, nor can you
>>tell some time later what did it. All you know is it was heat.
Rich you seem to have a one track mind that everything is parasitics. In
the SB-220 I can see at least 4 reasons for pyrotechnics in the RF deck:
- Parasitics
- Gas
- Mistuning... which will overheat the suppressor resistor and then it is
downhill from there.
- Secondary VHF reasonance in the tank...even when tuned properly on an
HF band.
Give it a rest please...will you? Tom and I have bitched at length and
will continue to do so at times I am sure; but we dont continue the same
F/N argument on for years.
Have a happy Thanksgiving ALL.
73 Carl KM1H
>Hmmm. So the changing resistance causes the tune capacitor to
>intermittently arc over?
>
> . . And on the starboard side, passengers can see part of the site
>of
>ancient Thebes. Its pharaonic remains include the Great Temple of Amen
>
>and a massive structure begun by Amenhotep III. On and on.
>... ...
>Rich...
>
>R. L. Measures, 805-386-3734, AG6K
>
>
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