Greetings to all,
Yes, I agree that there are better materials available for making
parasitic suppressors -- stainless steel is just one good example. But,
have you ever tried to fabricate a PRACTICAL suppressor out of stainless? I
have. I will take nichrome any day.
The basic idea of a parasitic suppressor is to lower the VHF/UHF Q
of the circuit it is installed in, not to support the generation of
VHF/UHF, as many commercial suppressors, made out of wide, silver plated
copper, do. They look pretty, offer no effect on VHF/UHF parasitic, and
have help keep me in business over the years. A workable suppressor will
have this attribute while having minimal effect on HF frequencies (I said
minimal effect, not zero effect).
It is not an easy job to design a parasite suppressor that work
from 1.8 MHz to 30 MHz. You need a good amount of inductance at the low
frequencies, but very little at the high HF frequencies. More times, than
not, if you have stuffiest inductance on 1.8 MHz, you will have way too much
at 30 MHz. This produces excess heat and usually causes the resistors to
overheat, and often causes them to burn up. Does this sound familiar? Your
suppressors work great on the lower bands, but overhear and burn up on 10
meters? This is why the loop suppressor were designed, about thirty
years ago (you may remember, Richard offered kits with these anode
suppressors for several years) . They were easily adjusted for the best
overall performance before being soldered parentally.
Don't forget that Art Collins was an early advocate of nichrome in
parasitic suppressors. He never said that it was perfect medium, just quite
functional.
73 de Lon, K5JV
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