> However, it does show that the more you think about screen supplies,
> the more potential failure modes you see, and the more complex the
> design becomes to defend against them. Marv's is complex; Acom's is
> complex; Alpha's is complex; and G4JZQ's and mine is complex. We all
> did it differently, but we all agree that a handful of cheap zeners
> won't cut it.
A handful of cheap zeners will cut it, if you power them from a
separate dropping resistor and keep the current through them
reasonably constant.
What I have done is power very low wattage zeners from the main
HV through a large dropping resistor, and use that as a reference
for a high gain transistor amplifier that does the regulating.
73, Tom W8JI
W8JI@contesting.com
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