[Amps] Ten-Tec Centurion

R.Measures r at somis.org
Thu Nov 11 09:34:55 EST 2004


On Nov 11, 2004, at 6:02 AM, k7fm wrote:

> Rich said:
>
> "Measuring the actual resistance of the parasitic suppressor resistors 
> and
> eye-balling their appearance could eliminate parasitics as a possible
> scenario in under 2-minutes - if the soldering-iron is hot. Not 
> measuring
> R-supp will not."
>
> Checking the parasitic suppressors at regular intervals is part of 
> regular
> maintenance.  However, logic seems to be against your theory of 
> paratistics,
> in this case.  You explain that hot switching is more likely to 
> precipitate
> the conditions for parasitics.  But, Tom said when he hot switched he 
> never
> had arcing.  Those two facts seem to reduce the liklihood that 
> parasitics is
> the cause.  It also increases the liklihood that timing is an issue.

Tom also said that the RF-resistance of Ni-Cr alloy decreases as 
frequency increases.    In addition, Tom said that the Laws of AC 
Circuit Analysis do not apply to VHF L/R suppressors.  Does this make 
sense to you, Colin?
>
> I do not want to discount your knowledge and expertise, and your 
> success in
> curing stubborn cases of parasitics, but you do tend to conclude that 
> almost
> every amplifier ailment is caused by parasitics.

I have had cases where tank arcing was caused by feculence that dropped 
down through the top and by a remote tuner's Tune-C arcing out in the 
yard.  However, I could be biased from autopsying too many tubes and 
measuring the R of too many VHF-suppressor resistors.

>  I happen to respectfully
> disagree with that view.  In some instances, you take a convoluted 
> path to
> conclude that parasitics is the cause, when there are simpler, more 
> direct
> possiblities, that do not involve parasitics.
>
Measuring R-supp would likely shut me up.

> And, I should warn you, that I do not have many skeletons in my closet 
> that
> you can use to discredit me (at least not that I know of).

That which discredits comes from one's own mouth, not from one's 
closet.  If you have not claimed to be a "recognized amplifier expert", 
and you support standard AC Circuit Analysis, you are doing well.
>
> But that is what this forum is for.

Presently, yes, but in the past, I have been jackbooted thrice by the 
AMPS "moderator" -- who, in each case, was a pal of the aforementioned 
"expert".
cheers, Colin

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org



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