> > The cure is a series "stopper" resistor of about 100 ohms, low
> > inductance, between the screen bypass and the larger capacitor. This
> > kills the parallel resonance completely, so the screen bypass works
> > correctly. To avoid introducing DC resistance (which increases the
> > source impedance of the screen supply, and may increase IMD) the
> > resistor can be paralleled by an RF choke, or you can wind about
> > 30-50 turns of wire on the resistor body.
That's what I would expect also, an oscillation at HF where the
tank is able to store energy.
It makes much more sense than VHF.
73, Tom W8JI
w8ji@contesting.com
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|