>> I now have a very useful amplifier. As to what the science or magic is in
>> the Nichrome suppressors, I don't give a rip. I'm just happy they work and
>> I'm quite happy to recommend them to anybody.
>>
>> 73, Alek
>> VK6APK
>
>Congratulations AGAIN, Rich.
>
> There is an old saying, the PROOF is in the PUDDING. If it works,
>let
>those who say it doesn't, explain why it does.
>
>Dave, WT8R
** Tnx, Dave but congrats are not appropriate because I was not the
first to discover that adding R to the anode's VHF resonant circuit in HF
amplifiers reduces VHF amplification. In the 1926-edition of The Radio
Amateur's Handbook, on page 72:
"The combination of both resistance and inductance (by using Ni-Cr
resistance-wire instead of Cu wire) is very effective in limiting
parasitic oscillations to a negligible value of current." -- F. E.
Handy
Apparently, the second person to discover that well-placed resistance
could improve stability was General Electric Company's G. W Fyler who
wrote ''Parasites in Transmitters'', Institute of Radio Engineers
journal. Sept. 1935. In conclusion, he said:
"In the elimination of parasites from a transrnitter, the circuits should
be kept as simple as possib1e to prevent complex resonance condition..
Radio frequency choke coils and shuntfeed circuits should be kept at a
minimum. Wide band neutralization circuits are desirable. The grids of
vacuum tubes should be effectIvely by-passed capacitively to the cathode
through a capacity, and inductance added next to the plates of the tubes
to eliminate shortwave parasites. If necessary, the plate or grid
parasitic circuits should be damped with resistance. Inductively coupled
rather than capacitively coupled Input and output circuits should be used
wherever possible. The mechanical layout of a shortwave transmitter
should be well planned with short lesds and compact tank circuits to keep
the current where it is supposed to be and to minimize stray coupling
between circuits."
- G. W. Fyler September, 1935
Thus, at best, AG6K was at least third, Dave.
cheerz.
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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