>
>Rich says:
>
>>Can you accept what is on the constant-current curves?
>Yes - but what has that got to do with it?
When the curve deviates, the resultant signal feculates.
>
>Quote again from Pappenfus et al. 'Most power tubes have a more linear plate
>characteristic operating Class AB2, however.'
>
My guess is that he is not all that familar with constant current curves.
Eimac rates two tetrodes for Class AB2 grid driven linear service.
> >I do not agree. Modern transceivers need a 50-j0 ohm load. With
>grid >current, the load Z on the exciter goes bananas
>
>
>Not necessarily so. It depend on the relative ratio of grid swamping to non
>linear grid current loading.
Tossing off the effect of rapidly decreasing grid resistance as grid
current flows does not wash. .
> Additionally, you appear to assume that the
>input impedance of grounded cathode AB1 stage is constant and high.
[chortle]
>This is
>not necessarily so - because of Miller effect.
>
>If the driver has adequte NFB to reduce its output impedance, the effects
>are minimised.
>
I know of no commercial radio that works well with other than a 50-ohm
load.
cheers, Peter
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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