>What is Rp??
Rp is the parallel equivalent of a series circuit.
> Normally when ones talks about voltage gain for a triode it is:
> MU*Rl/(Rl+Rp)
>A VHF suppressor is not in parallel with the plate circuit but in series.
Every series circuit has a parallel equivalent. Every parallel circuit
has a series equivalent. Rp fits into the voltage amplification
equation.
>The question as I see it is that if the lead to the Pi, or Pi-L produces hi
>vhf gain you must raise its impedance at VHF. This the normal vhf choke
>over a resistor does.
I disagree. The anode's VHF self-resonant circuit has a high Rp unless a
VHF suppressor is used. Less VHF-Rp equals less VHF voltage
amplification. The purpose of the VHF suppressor is to reduce VHF
voltage amplification.
>Adding resistance wire lowers the performance on the
>low bands as it does at VHF. What am I missing?
During the VHF parasitics debate, the naysayers often said that
suppressors made from resistance-wire would have a disastrous effect on
10m harmonics. According to Wes' (N7WS) measurements, the
resistance-wire suppressor exhibited 4.32 ohms of ESR at 30MHz. The
output Z of the tube was about 4000 ohms, and the reactance of the anode
C was about 1100 ohms. Is 4.32 ohms comparitively significant? I
repeatedly asked the naysayers to prove their allegations with
calculations. None did. Perhaps you could enlighten us, Jerry?
[note---Wes made no measurement of the W8JI-suppressor's ESR at 30MHz.].
As the donnybrook continued, one "expert"/naysayer expanded the alleged
disastrous effect to include everything down to 160m. Move over,
Chicken Little.
> A final note. Read the articles in QST etc. Didn't believe then and
> don't
>now.
However, I'm betting lunch at the Somis Cafe that you believed every word
in the September 1994 QST's Technical Correspondence column, Jerry..
> 73 de NO2T Jerry
Rich---
R. L. Measures, 805-386-3734, AG6K
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