>
>> >Now I didn't test every PA in the world, but the case where anode C is
>> >more than distributed capacitance in the PA and the lead between the two
>> >C's happens to form a step-up transformer doesn't occur in any PA I
>> >have....even though Rich claims it can.
>>
>> That doesn't mean it can't happen - only that you haven't seen it.
>
>To be more specific:
>
>It means I have not seen it in PA's where Rich claims the
>bandswitch is damaged by VHF oscillations.
>
>> >Tell me the flaw in my measurement method, exciting the anode of
>> >the tube at the anode with a high impedance bridging source and
>> >measuring voltage along the tank system.
>>
>> Getting a sufficiently high impedance of R very high in series with
>> absolutely j0.
>
>The R only has to be a value somewhat higher than the dynamic
>impedance of the anode in operating conditions, unless you buy
>into the theory that power grid tubes with no plate current can
>oscillate with considerable energy.
>
>Ignoring the anode resistance can make all sorts of odd theories
>work.
>
>> >Remember we have to destroy the switch, which is further
>> >downstream....
>>
>> Assume the stray capacity to ground from the switch end of the first
>> section of the tank coil series resonated at the parasitic frequency with
>> the first bit of tank coil?
>
>Then the input impedance is reduced.
>
>> I'm saying you cannot explicitly rule out the possibility of step up as
>> far as the tank capacitor, or even to the switch. The probability of it
>> happening is pretty mind boggling low as you need the resonances of
>> several sets of components to all tie together. About the same as my wife
>> winning the first prize in the lottery this weekend. But not impossible.
>
>I can measure it. If you wife looks at the lottery payoff, and it is a
>different number, the chances of her having won are what we can
>consider zero.
>
>> After all, even a stopped analogue clock is right twice a day!
>'
>Not one without any hands. When a person says something
>happens in a specific device, and then measurements prove it
>can't, it is time to re-think the speculated cause of the problem.
>
>Now like you, I'm not saying an oscillation can't damage a PA. I'm
>just saying the most likely scenario is an oscillation at or near a
>frequency where the tank is resonant.
>
>I'm sure Rich's suppressors would help PA's like Clipperton L's,
>because they oscillate on or near ten and 15 meters. They aren't
>the only way to fix the problem, but they de-Q the tank near ten
>and 15 meters.
>
>Conventional suppressors, while behaving the same or better at
>VHF as nichrome varieties, don't de-Q the system at HF nearly as
>much.
>
Mr. Rauch -- Your statements contradict Wes' measurements.
>
end
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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