>It is often said in amateur circles that the choke is there to provide a
>safety
>ground if the feed capacitor from the plate goes short circuit. In that case,
>the choke has to be pretty 'hefty' in that it will need to blow the HV
>fuse or
>whatever without burning up itself, and the usual 2.5mH choke will
>literally be
>toast long before that happens with a big amplifier. As Rich says, to just
>bleed the dc of the tuning and loading capacitors, resistors are adequate.
>
>I've never had a case of the feed capacitor going short circuit, although
>that
>doesn't mean it hasn't happened.
>
** If the HV DC-blocker shorts, the typical load-C will arc to ground
and blow the primary HV fuses. // On a windy day, I have measured up
to 3kV of static charge on an 80m anrenna, so a bleeder resistor is
seemingly good engineering practice. An output bleeder-R also provides a
good way to measure relative RF-output V. Add a 100-ohm resistor from
the cold end of the bleeder to ground and connect a diode to the junction
to furnish DC to a tuning meter. hote -- This is more useful in a g-g
amp than in a grid-driven amp, where the tuning is done instead with the
screen-current meter.
cheerz, Peter.
- Rich..., 805.386.3734, www.vcnet.com/measures.
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