>
>Hi Skipp,
>
>I have a serious question, and I think the answer would be of great
>use to many people.
>
/\ Quite possibly not to those who read AMPS without a filter, Mr.
Rauch.
>> So I did the proper math home work to figure out
>> the coil inductance values for my suppressors which
>> were right in line with Rich's paperwork. My math
>> and testing came up with inductance values about
>> 85 to 95% of the suppressor kit values.
>
>Can you share the formula you use in determining the amount of L
>and R required to stabilize an amplifier?
>
/\ There is nary a magic answer or esoteric formula.
- In "Parasites in Transmitters" (1935) Mr. G.W. Fyler said that adding
resistance to parasite-resonant circuits is the cure. Determining how
much resistance is largely a trial and error process aided by educated
guesswork and pervasive glitch* protection.
>I can use a series of measurements to determine the approximate
>value of R and L in most cases, but I've also found many cases
>that require testing of several PA's to optimize suppression. A
>simple formula would certainly save work!
>
/\ First off, one needs to realize that roughly equal currents need to
flow in L=supp and R-supp at the anode's VHF resonant freq. Secondly,
the electromagnetic fields of R-supp and L-supp need to be perpindicular.
Thirdly, adjust L-supp to cause R-supp to dissipate maximal heat at
29MHz.
- But alas, I know it is definitely difficult to teach old dogmatists
new tricks.
>
cheers
* American Heritage Dictionary:
- "Probably from Yiddish glitsh, a slip, lapse, from glitshn, to slip,
from Middle High German glitschen" ...
- WORD HISTORY: Although in retrospect glitch seems to be a word that
people would always have found useful, it is first recorded in English in
1962 in the writing of John Glenn: ³Another term we adopted to describe
some of our problems was ?glitch.¹² Glenn then gives the technical sense
of the word the astronauts had adopted: ³Literally, a glitch is a spike
or change in voltage in an electrical current.² In this very passage we
see how the word moved from its narrow, technical electronic sense to a
more general sense, even if the astronauts were not necessarily the first
to extend the meaning of glitch. Since then the word has passed beyond
technical use and now covers a wide variety of malfunctions and mishaps.
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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