----- Original Message -----
From: "Tom Rauch" <w8ji@contesting.com>
To: "2" <2@vc.net>; " AMPS" <amps@contesting.com>
Sent: Monday, March 03, 2003 10:41 AM
Subject: Re: [Amps] Toroidal Tank Coils
> > Mr. Rauch -- 80% of 4000V = 3200V. 90% of 4000V = 3600V. What's the
> > problem with 3500V?.
>
> Your normal diversion is to lift things out of context. The rest of my
> answer explains the difference.
>
> > >which would translate to 3kV or more across the tank inductance.
> > >The exact value depends on tank loaded Q, which sets phase shift across
> the
> > >inductance. Q's of 10-12 result in about 130-degree shift,
> >
> > And I thought the phase shift in an inductor was 90?.
>
> You thought wrong.
>
> Phase shift depends on reactance and circuit impedances. A series inductor
> only causes a 90-degree shift when the load impedance is zero and the
> inductor is infinite in value.
>
> In a pi-network tank system we have shunt capacitive reactances at each
end,
> and a series inductance. The ratio of those reactances and the termination
> impedance of the network determines the phase shift. It is 90-degrees in a
> minimum Q network that matches two impedances, because the network behaves
> like a 1/4 wl transmission line with a surge impedance equal to the
> geometric mean of the load and source impedances. The same formula that
> would apply to a 1/4 wl transmission line applies to the CLC or LCL
system.
>
> In a pi, that is behaving like a pi, the network is two back-to-back L's.
> This allows us to set phase delay over a wide range when matching two
> impedances. There is no difference in talking about phase shift or Q.
Either
> one can be translated into the other.
>
> This is why some engineers baffle people by speaking about phase shift in
> tanks. They are really describing Q.
>
> Thank goodness things work the way they do, and not the way you thought
> Rich! We would be in big trouble designing tank circuits and variable
phase
> shift networks!!
Is not what you describe, the phase shift caused by the entire network? ie:
EI angle at C-tune vs EI angle at C-load?
Rich speaks of the E I shift in an inductor which is something near or less
than 90 degrees.
Someone help me please (with minimum bovine feculence) as I'm getting
confused.
Jeff
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