> How useful is a bias voltage that wanders with temperature?
>
> If you have 10 diodes to get about 7 volts, that will reduce by over
> 1/4 volt for a 20 degree rise.
>
> Of course, the ZSAC may be so non critical that it doesn't matter on
> 3-500Zs, but if you're going to start pushing the output power,
> carfeul selection of the right zeners could help.
>
> After all, it's only a relatively few dollars for a number of big
> zeners - a lot more for the tubes. even less with 1 watt zeners and a
> 2N3055 or similar beefy transistor.
Peter,
Rich suggests series rectifiers as zeners. Like with neutralization
or parasitics, nothing else in the world except his exact ideas are
acceptable.
It doesn't matter if the regulation is worse with temperature, or if the
bias voltage wanders around with current, as long as you follow his
commands.
73, Tom W8JI
w8ji@contesting.com
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