At 11:11 AM 2/23/2005 -0500, you wrote:
Ok that is fine. For reasonable values of Q the "1" is on the order of
variables you have no control over such as tolerances, parasitic
reactances, variations in tubes etc. That is why I simplify things to
Ri/Ro=Q^2. Ri being the High-Z. end of the L network. Maybe it would be
better to say Rhi/Rlow=Q^2. For a Q of 10 the difference is 1 percent. Not
something to worry about in terms of SWR (1.01:1.00). I have used a Q of
10 because the output network not only is used to match impedance but to
reduce harmonics.
For a single PI network you will probably want a Q of 20. So the "+1" even
becomes less significant.
For those that have tried the amplifier resonance test, the apparent
shift in resonance most likely due to the change of input impedance shift
of the input of the amplifier as you change the tune capacitance. You may
notice a change in the grid current or exciter to amplifier SWR as you
change plate tuning capacitor.
73
Bill wa4lav
>
>Hi Rich,
>Before getting into this discussion too deeply, are we all in agreement that
>the fundamental parallel to series equivalent and series to parallel
>equivalent mathematics are correct and accepted by everyone?
>
>Specifically:
>
>Rs=Rp divided by (Q^2+1)
>
>Rp=Rs multiplied by (Q^2+1)
>
>Q in a parallel circuit= R divided by X
>
>Q in a series circuit=X divided by R
>
>Xp=Rp divided by Q
>
>Xs=Rs times Q
>
>Rs=series resistance
>Rp=parallel resistance
>Xs=series reactance, + for inductive, - for capacitive
>Xp=parallel reactance, + for inductive, - for capacitive
>
>Stopping at this point for now. Any disagreement so far?
>
>73,
>Gerald/K5GW
>
>
>
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