----- Original Message -----
From: "Bill, W6WRT" <dezrat1242@yahoo.com>
To: <amps@contesting.com>
Sent: Thursday, July 29, 2010 6:31 PM
Subject: Re: [Amps] More parasitic choke questions
> ORIGINAL MESSAGE:
>
> On Thu, 29 Jul 2010 16:27:58 -0400, "Carl" <km1h@jeremy.mv.com> wrote:
>
>>I dont understand how moving the resonant frequency of the coil up and
>>using
>>the same resistor raises the Q?
>
> REPLY:
>
> If you are talking about the suppressor coil, it is not resonant and
> has little effect on the VHF parasitic frequency because it is
> bypassed by a low value resistor. Its purpose is to provide a
> low-impedance path for the HF current around the resistor.
>
> If one did not care about bypassing the HF around the resistor, one
> could have only the resistor without a coil at all and the parasitic
> suppression would be equally effective. Power loss would be high of
> course, but it would work. I have never seen it done that way and I
> mention it only to help folks understand what the purpose of the coil
> is. I am not recommending it.
>
> 73, Bill W6WRT
Your understanding of parasitic suppressor design is 180 degrees opposed to
reality. I suggest that you study up on the subject instead of inflicting
new amp builders and others who apparently also dont understand the subject
(but feel the pressing need to comment) with such pathetic misinformation.
Carl
KM1H
.
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