I think what you see here is maximum power transfer that occurs when the
source impedance is equal to the load impedance .
Without the network, they are not equal.
With the network , well , they are.
---
Ron
Jon Ogden wrote:
>
> on 1/14/02 5:45 AM, Tom Rauch at w8ji@akorn.net wrote:
>
> > A matching system in a GG class B or AB amplifier serves three
> > important functions:
> >
> > 1.) It matches impedances
> >
> > 2.) It provides a low impedance path to the chassis for tube
> > cathode harmonics
> >
> > 3.) It prevents cathode harmonics from reaching the exciter and
> > causing problems
> >
> > You can't do that with a broadband transformer. It requires a low
> > pass network with a low-reactance capacitor (compared to the
> > tube's driving impedance) shunting the tube cathode to ground.
>
> Tom,
>
> Correct me if I am wrong, but doesn't the literature lists one more reason
> for having an LC based matching network in you amp? It tends to act as an
> energy storage medium for when the tube is in cutoff - the old flywheel
> analogy. A transformer wouldn't do the same thing. Or do I have it wrong
> in that this "flywheel" analogy only applies to the tank circuit on the
> output of the PA...........
>
> 73,
>
> Jon
> NA9D
>
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--
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