Have also seen this used in the Granger 172-2 MF/HF 5 kW amplifier.
Two 100 ohm Globar resistors were placed near the anode cooler of the P-290A,
with one end grounded and the other end "floating".
The designer's motivation for these resistors was that they were supposed to
damp
out a tube dimension related parasitic resonance in the high VHF range.
73/
Karl-Arne
SM0AOM
----- Original Message -----
From: "Jim Tonne" <tonne@comcast.net>
To: <conrad@g0ruz.com>; <amps@contesting.com>
Sent: Monday, November 07, 2005 3:14 PM
Subject: Re: [Amps] Grounded Screen 4CX1500B
>
> Conrad:
>
> Regarding a resistor in the PA cabinet, absorbing harmonic
> energy: it is not anedotal! Quite true, being used at
> Continental Electronics.
>
> But the position is important and has to be done by cut and
> try methods. This technique was used for both stabilization
> and for VHF/UHF harmonic control.
>
> - Jim Tonne ex-Continental guy now enjoying retirement
>
> > Shawn I operated the 2m amp for several years on eme. There was a problem
> > with the 3rd harmonic which appeared to be a result of cavity resonances
> > in
> > the output compartment. I cured it with a 100 ohm large carbon resistor
> > placed on one wall of the cavity, grounded at one end.
>
>
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>
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