-----Original Message-----
From: measures <2@vc.net>
To: amps <amps@contesting.com>
To: <amps@contesting.com>
Date: 07 September 2000 17:34
Subject: Re: [AMPS] Blown TL922A... What to do?
snip
Steve:
>>> Adding a L/R parallel circuit in series with the capacitor introduces
loss
>>> as the frequency increases, but does not introduce multiple resonances.
As
>>> I understood what he said, Rich suggested that the separate current
paths
>>> through the L and the R should produce multiple resonances. I said then
I
>>> thought his analysis was wrong. I still do.
>>
Tom:
>>Rich's analysis is wrong.
>
>Rich did not say this. The discussion of current division in L-supp and
>R-supp had Nothing to do with the discussion about series resonances in
>C-Tune.
I'm sorry if I misunderstood you, Rich. This is your comment I was referring
to (taken from a post of mine on Aug 8th):
? A parasitic suppressor has two current paths whose EMFs are decoupled.
Thus, the higher inductance path (L-supp) resonates the anode a bit
lower in freq. than does R-supp. The effect is similar to stagger-tuning
an IF transformer to reduce Q/increase bandwidth. .
I read that as suggesting that there are two resonances.
As far as I can measure, the series resonance in the tune C is dominant - I
revisted my measurements by adding a shunt C to simulate the anode
capacitance of the tube. Looking at the impedance as seen from the tube
anode, it changes the resonant frequency a bit, but otherwise the overall
characteristic remains the same. There is a single series resonance in the
low/mid vhf region, and the impedance stays low either side of it. When I
next get the bench clear (might be a while), I'll run some plots. Please say
if there are any particular configurations you (or anyone else) would like
me to try and simulate to measure.
Steve
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|