>
>> Help me here. Isn't this the purpose of the suppressor? That is , it's
>> function in design is not only to limit parasitic currents to a
>> "negligible level," but more importantly "suppress" the oscillation from
>> occuring "in the first place?"
>
>The goal is to prevent oscillation. That's done generally done by
>inserting a series resistance that is reasonably large compared to
>the anode path impedance.
>
>The shorter the anode lead, and less reactive, the less resistance
>you need add. Other things come into play also, but it isn't
>extremely complicated.
>
>> Perhaps, unless Rich uses the material "in fair use," as provided for in
>> the U.S. copyright law. Additionally, violations to copyright law are not
>> limited to "for profit" references. Adding web links for general
>> distribution (e.g., Wes's link to this mail list) without the express
>> consent of the copyright holder can also lead to copyright infringement.
>
>I think the main complaint by Wes was a gentleman's agreement
>to NOT corrupt or distort the data was broken.
>
? No one changed anything. The bottom-line is that the copper-wire
parasitic suppressor had 40%+ more Q at 100MHz than the resistance-wire
parasitic suppressor. The choice is simple. Those who want more VHF
gain at 100MHz can choose the copper-wire suppressor. Those who desire
more heating in R-supp at 29MHz should choose the copper-wire suppressor.
>You should ask Wes about that.
>
>> I too am perplexed by the ongoing suppressor controversey and it's
>> function seems to be nearly as mystical as that accorded by the dreaded
>> balun.
>
>Baluns are easily understood, except for those who want it to be a
>simple one word answer.
>
Amen, Tom.
>> nearly every commercially-manufactured amateur amplifiers when most of the
>> same manufacturers would have you believe that 1) their amplifiers are
>> ultimately stable, and 2) suppressors are not required in
>> "well-engineered" designs. If conditions 1 & 2 are met, isn't it
>> ridiculous to include the suppressors in their designs? Or, is the
>> inclusion of the suppressor in their amplifiers that little bit of
>> insurance against "the unknown?"
>
>In some cases suppressors are needed, in some they are not.
>Sometimes they are included just because people think they
>should be there.
>
>> Seems like Rich has worked toward an alternative method suppressing
>> parasitics that is no more costly or dangerous to the performance of a
>> H.F. amplifier's design than that provided for by the standard use of the
>> classic coiled wire on a carbon composition resistor.
>
>There is little harmful in using his suppressors. The real harm is in
>the wave of sideways thinking that has been produced by bad
>theories and junk science surround the causes of failures.
>
? This, from the guy who claimed that standard AC circuit analysis
won't work with parasitic suppressors. // My favorite sea story is
''disappearing barnacle flashovers''. These are arcs that leave no
visable arc mark, yet make a stentorian big-bang in a vacuum. Are we
talking unsliced bologna or what?
>The only harmful advice I'm aware of is his suggestion that grid
>protection circuits are not necessary in metal oxide cathode tube
>amplifiers.
>
The intrinsic problem with transistorized grid protection is that
typically a 1a transistor is expected to be able to shut off the flow of
many amperes of grid current during a major parasitic event. Nacherally,
the transistor shorts and protects not. A fast acting 250v fuse,
shunted by a 120v MOV would be a better choice. The MOV serves to
extinguish the metal vapour arc that appears as the fuse opens. Also, it
seems to me that the key to preventing gold sputtering from the grid
during an "oscillation condition" is to use a suitable glitch resistor in
the positive hv supply to limit peak fault current from the filter
capacitors.
>While the nichrome doesn't fix much if anything,
Is 40% more VHF Q better? A resistance-wire suppressor reduces the 10m
dissipative burden in R-supp. Is that good or bad?
> it only hurts ten
>and 15 meter efficiency bit. So it really isn't harmful.
>
? What could happen if R-supp burns out?
Why should all of this be so controversial?
later, Tom
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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