> Steve said:
>>In every case so far, copper gives
> better 'goodness'.<
> Which, from purely a theoretical viewpoint, is exactly
> what should be expected.
> Peter G3RZP
N7WS measured identical magical nichrome and conventional
Ameritron suppressors, and found at VHF near the frequency
of suppression there was essentially no difference at all.
As frequency was reduced to HF and lower, the nichrome
suppressor remained lossy.
A nichrome or other lossy resistive conductor suppressor is
NOT a "low-Q VHF suppressor". It is actually a low Q low
This makes perfect sense and follows conventional wisdom,
since the primary path for lower frequency signals is
through the inductor. The primary path for VHF and highest
frequency signals shifts into the resistor. Thus the coil
loss affects dc the most, and UHF the least. The resistor
affects UHF and the highest frequencies the most, and dc the
By adding a resistive conductor we lower HF Q the most,
while barely changing VHF Q.
If I had an amplifier that was unstable at or near the
operating frequency and if I couldn't neutralize the
amplifier, adding resistance that swamps the signal
frequency might be a solution. If I really had a VHF
oscillation in an HF amplifier then the solution would be
increasing inductance and SHUNT resistance.
It's amazing how such a very simple system has become so
misunderstood, almost to the point of being voodoo.
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