>>While I agree that the whole tank circuit in a tube IS VHF resonant,
>
>I do not. The HF tank circuit is a lowpass filter. The VHF resonance
>at hand involves the anode-grid C, the total inductance of the conductors
>between the anode connection and the Tune C, and the capacitance of Tune
>C. Typical resonance frequencies are from roughly 65MHz for largish
>tubes like the 8171, to roughly 170MHz for small ceramic tubes like the
>3cx800A7. . The VHF resonance picture is further complicated by VHF
>self-resonances within the Tune C. . . Murphy was seemingly right.
>Things are usually more complicated than they look.
I stand corrected. I think I meant the VHF tank circuit created by the
stray capacitances and inductances in the tube, anode and tune C
circuits. Yes, the output PI-network IS a lowpass filter.
73,
Jon
KE9NA
--------------------------------------------------------------------------
Jon Ogden
jono@webspun.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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