>Hi Rich and all,
>
>> Ä John -- The same statement (by Ehrhorn) was in the '95 Handbook. This
>> was before Wes' tests with the Hewlett Packard Impedance Analyzer. The
>> test evidence showed that a resistance wire suppressor lowers VHF-Q by a
>> bit over 40%. This is probably a conservative number because we currently
>> use resistance wire that has about 70% more resistance than the wire used
>> in Wes' tests. However, if resistors were available that had roughly 10nH
>> of L, And would dissipate at least 30w, an even lower VHF-Q suppressor
>> could be built with copper wire. Cesiwid Co. told me they could
>> manufacture such resistors. The asking price for a min. order was about
>> 10 kilobucks.
>
>That's your opinion Rich. If you ask Wes, the fellow who made the
>measurements, his conclusion is different than yours.
>
? According to Wes' measurements, at 100MHz, the resistance-wire
suppressor had about 41% less Q than the copper-wire suppressor. Is
higher Q in a VHF suppressor better?
>Same old song, same old dance no matter what the music is..
>
AC Circuit Analysis will always be the same. Your legacy may be that you
are the only ham radio operator who ever claimed that AC circuit analysis
does not work for VHF parasitic suppressors.
>Wes actually concluded the only place nichrome seriously lowered
>the Q was at HF...not at VHF.
? Interested parties should read the measurements and make their own
conclusions.
>That makes sense since the
>inductor has more current at HF than VHF, and the resistor gets
>more current at VHF where the inductor impedes the current flow.
>
In my opinion, your theory that current is choked off by coils at VHF is
thick-sliced bologna. In an optimally-designed suppressor, at the VHF
parasitic frequency, roughly equal current division takes place between
L-supp and R-supp.
>No one expects you to change at this point, you have too much
>time invested in the claims you make.
>
The claim I make is similar to -
³The combination of both resistance and inductance is very effective in
limiting parasitic oscillations to a negligible value of current.² F.
E. Handy, 1926-edition of The Radio Amateur's Handbook, page 72. In
1935, G. W. Fyler elaborated on the value of adding resistance to improve
VHF stability. . To me, the amazing thing is that what Messers. Rauch,
Telewski, Ehrhorn, and other critics of the four *QST* articles on
parasites are essentially saying Iis that resistance from resistance-wire
is of no value in VHF dampening devices.
>
The long excursion on the wide river in the Land of the Pharoahs
continues.
later, Tom
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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