>>When the DC blocker fails without a "safety choke" being present, the
>>Load C itself acts as a protective spark gap, arcs, and shorts the HV to
>>ground.
>
>A lot of the 'safety' chokes I've seen burn up if the blocking cap fails -
>they can't take the DC from a PSU capable of an amp or more.
The safety choke should be matched to the primary CB's or fuses to be
robust enough to withstand the current fo the time it takes for the fuses
to blow.
? whereupon the Load C arcs to gnd - which puts the DC supply out of
business.
IMHO, using a very expensive "bread slicer" variable cap or even worse,
a VERY expensive vacuum variable load C as a spark gap to do the
job of a $5.00 safety RF choke is very poor engineering practice, indeed!
Why wait for the "big bang" when the RF choke will bleed off all charges
large and small; whether coming from the block cap, the tank circuit,
or even static build-up from the antenna.
(((73)))
Phil, K5PC
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