This same subject was discussed 2 months ago almost to the day. Look in the
archives for "plate bypass capacitor". It started on 8-8-2009.
It was shown that the plate choke can be part of the resonant tank circuit
when its inductance is low. Yes it does have rf current through it and its Q
needs to be high enough to keep losses down in the choke. This is commonly
done in many amplifiers.
73
Gary K4FMX
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> Behalf Of Bill, W6WRT
> Sent: Tuesday, October 13, 2009 6:24 PM
> To: amps@contesting.com
> Subject: Re: [Amps] Checking Plate Choke resonance
>
> ORIGINAL MESSAGE:
>
> On Tue, 13 Oct 2009 09:53:00 -0700, Vic K2VCO <vic@rakefet.com> wrote:
>
> >
> >I don't see how a parallel resonance would hurt, since it would create a
> very high
> >impedance, which is desirable.
>
> REPLY:
>
> The parallel resonance is accompanied by very high circulating current in
> the
> choke. If you think about it, your pi-network is also a parallel resonant
> circuit with high circulating current even though it is loaded by the
> antenna.
> The RF choke has no such load and the circulating current is even higher.
> Since
> the RF choke is normally wound with small wire, smoke will soon follow.
>
> 73, Bill W6WRT
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