Peter Chadwick wrote:
>
> I use resistors across the diodes, with no capacitors. With 1kV diodes, I
> use two 500volt resistors in series, although that's probably 'belt and
> braces'. If I was using capacitors, they'd be .01 microfarad 1kV working
> micas or plastic film, not disc ceramic, because of temp co and tolerance.
> I've never had hash caused by the diodes switching abruptly, either. With
> 1N5400 series, they're relatively slow, so I wouldn't expect it.
30-odd years ago, I worked at a BC station. We had a 5kw FM transmitter whose
power supply contained boards made of many, many 400 piv diodes. They were
paralled with (I think 470K) resistors. We lost quite a number of boards
(sounded like a machine gun when they went). We tried to match resistor values,
etc. to no avail. At some point, someone suggested that we use .001 uf
capacitors instead, and after that we had no further problems.
So far, the advice I've received has included 1) don't put anything across the
diodes, 2) put only resistors across the diodes, 3) put only capacitors across
the diodes. I'm leaning to the capacitors, because of my ancient experience.
73,
Vic, K2VCO
Fresno CA
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