From: <color><param>0000,0000,8000</param>"Tom Rauch"
<<w8ji@co=
ntesting.com>
</color>To:
<color><param>0000,0000,8000</param>amps@contesti=
ng.com
</color>Date sent: <color><param>0000,0000,8000</param>Mon, 7 Jun
19=
99 07:16:30 -0400
</color>Subject: <color><param>0000,0000,8000</param>Re: [AMPS]
TL=
-922 Filament Transformer Protection
</color>Send reply to:
<color><param>0000,0000,8000</param>W8JI@contesti=
ng.com
</color>Priority: <color><param>0000,0000,8000</param>normal
</color>Subject: Re: [AMPS] TL-922 Filament Transformer
Protection
Date sent: Sun, 6 Jun 1999 08:29:51 -0700
From: Rich Measures
<<<underline><color><param>0000,8000,0000</=
param>measures@vc.net</underline></color>>
To:
<<<underline><color><param>0000,8000,0000</param>W8JI@con=
testing.com</underline></color>>,
<<<underline><color><param>0000,8000,0000</param>amps@contesting.com</unde=
rline></color>>
I wrote:
<italic>> >The "omission of fact" that you used to distort the answer was
that the
> >particular capacitors I measured with high VHF low UHF
resonances
> >contained SERIES resonances, where the impedance went
through a wide DIP
> >in impedance.
> >
> =80 What is the likely Z of a high-Q series-resonant circuit on
> frequencies above and below the frequency of resonance? As I
recall, you
> measured an AL80 Tune-C series-resonance at c. 180MHz, and
the parasite
> took place c. 160MHz.
</italic>I expect you to "look for" a parallel resonance in the capacitors=
Rich, and claim there must be one (without measuring properly)
because without a crummy capacitor that has hundreds or
thousands of ohms of VHF impedance your entire "a VHF parasitic
arced the bandswitch" theory falls square on its nose.
So of course you want to "invent" a parallel resonance below the
series resonant frequency! Otherwise everyone who swallows your
parasitic BS would see through the farce!
But common sense prevails in many people. If a capacitor had a
parallel resonance at VHF, the amp would be TVI trash-city. It
would probably never pass FCC tests for harmonics measured at
VHF. Virtually all amps show a smooth rapid decrease in
harmonics with increasing frequency. None I've ever seen have the
Hi VHF Z capacitor you desperately search for. Without it, your
VHF bandswitch fantasy can not be true.
The capacitors typical to AL-80's, SB-1000's, SB-220, L4B's and
so on have a smoothly decreasing impedance up to a minimum of
almost zero ohms at 180 MHz. Above that the impedance slopes
slowly back upwards in reactance with the opposite sign. The ones
I measured don't look like a high Z at any frequency until up around
400-500 MHz or higher, and even then the impedance isn't all that
high.
Maybe you should change your song and dance to UHF or
Microwave parasitics?
<italic>
> >You did the same thing with the measurements N7WS made on
> >suppressors. It seems to be your pattern.
>
> =80 According to Wes' measurements, there was about a 40%
decrease in
> VHF-Q with the resistance-wire suppressor compared to the
copper-wire
> suppressor. Are you suggesting that more suppressor Q
equates to more
> stability?
</italic>Wes' conclusion (that HE posted) was there was no real difference=
between the suppressors. You are the one who changed that post
by omitting facts and misapplying data. As you typically do.
73, Tom W8JI <underline><color><param>0000,8000,0000</param>w8ji@contestin=
g.com</underline></color> <color><param>0100,0100,0100</param>
73, Tom W8JI
w8ji@contesting.com
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|