----- Original Message -----
From: "Bill, W6WRT" <dezrat1242@yahoo.com>
To: <amps@contesting.com>
Sent: Thursday, July 29, 2010 3:41 PM
Subject: Re: [Amps] More parasitic choke questions
> ORIGINAL MESSAGE:
>
> On Thu, 29 Jul 2010 08:12:48 +0700, "Martin Sole"
> <hs0zed@csloxinfo.com> wrote:
>
>> It certainly suggests there might be
>>more than a couple of watts in the R on 10m.
>
> REPLY:
>
> The amount of power dissipated in the suppressor resistor on ten
> meters can be controlled by using more or less inductance in the coil.
> Less inductance = less dissipation, but also less de-Qing of the VHF
> parasitic tank circuit. It is a delicate balancing act to get it just
> right.
>
> 73, Bill W6WRT
I dont understand how moving the resonant frequency of the coil up and using
the same resistor raises the Q? More inductance than necessary will result
in more possibility of absorbing the wanted RF. On a HF amp there is not
much balancing required with most tubes. It does become critical on 6M using
tubes with a parasitic around 70-80 MHz.
If the parasitic is at 120-150 MHz as with a 3-400/3-500 there should be no
(measurable power for nit pickers)10M power in the resistor
Carl
KM1H
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