Note -- attribution marks added by yours truly.
>Rich said:
>
>>"5) My position: Trying to squeeze out the last watt at 29MHz is probably
>>not going to do much for reducing VHF gain. History tells those who will
>>listen that betting against Mr. Murphy is
>>neither likely to be good engineering practice or likely to be profitable."
>
>Rich, you have been arguing that your suppressors are a little bit more
>lossy at 29 mHz and that this is proof that they are better than stock
>parasitic suppressors at suppressing parasitics that may be occurring at 100
>to 200 mHz. In fact, the parasitic oscillation rarely occurs at 29 mHz, so
>the argument does not carry weight.
** Is it possible to design a VHF suppressor that suppresses 100MHz, but
does not suppress 30MHz ?
-- The lowest parasite I know of was at 43MHz. The Plywood Box 4cx5000A
amplifier had one c. 68MHz until I took G. W. Flyer's advice.
>Your position seems to be that since
>nichrome is lossy at all frequencies, it must necessarily be better at
>suppressing parasitics at vhf.
** Not quite. The key to suppression is to add R. If one is trying to
add R, does Cu or Ag sound like a reasonable way to go ?
>This may miss the point. Parasitics may
>occur over a small range of frequencies. If the designer carefully designs
>a parasitic suppressor that is custom designed for that amplifier, that will
>solve the parasitic problem.
** How does one go about designing a VHF notch suppressor ?
>While the use of nichrome in a parasitic
>suppressor may solve the problem, it also may be considered a shotgun
>approach. There is no black magic surrounding nichrome.
** true, Ni-Cr alloy only has more R than other metal conductorss -
and it does this from DC to light.
> It may have been
>an excellent solution in 1936,
** 1926 -- by Mr. F.E. Handy.
>when it was suggested, because we did not
>have adequate test equipment to scientifically analyze parasitics and
>amplifier layout.
>
** Mr. Handy relied on measured grid-current.
> ...
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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