Tom Rauch wrote:
>> 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.
>
I should have said "won't cut it on their own" - and that rather proves
the point.
--
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.com/g3sek
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