[Amps] .01uf caps across diodes ?

[Jim W7RY]

Agreed.

Jim W7RY


On 12/12/2022 12:32 AM, MU 4CX250B wrote:
> Hi Tim,
> I’ve followed this debate for years and frankly I don’t think adding
> .01uF caps across each diode in a diode string makes much difference
> one way or the other. It’s true that there will be some suppression of
> fast current and voltage transients, but these aren’t likely to cause
> damage to modern components. To me the downside of the practice is
> that adding 0.01uF caps results in additional opportunities for
> capacitor failures, loose solder connections, unsightly wiring, and a
> bunch of extra components that provide minimal benefits. I’m inclined
> to leave them out. (BTW, one commenter suggested that sharp voltage or
> current spikes wouldn’t make it through the filter capacitors. That’s
> untrue because the filter caps have a self inductance that keeps them
> from filtering spikes with high frequency components. )
> 73,
> Jim W8ZR
>
> Sent from my iPhone
>
>> On Dec 11, 2022, at 7:03 PM, Tim Duffy <k3lr at k3lr.com> wrote:
>>
>> W8ZR Jim
>>
>> Can you give advice on this topic?
>>
>> 73
>> Tim K3LR
>>
>> -----Original Message-----
>> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of jim.thom
>> jim.thom at telus.net
>> Sent: Tuesday, November 29, 2022 2:28 PM
>> To: amps at contesting.com
>> Subject: [Amps] .01uf caps across diodes ?
>>
>> What's the consensus on wiring .01uf disc caps across diodes in a HV supply
>> ?
>> W8JI sez they are required, and used in ameritron amps....and used to
>> eliminate switching transients.
>>
>> Some say the caps are required to meet emc specs on commercial gear.
>>
>> I can't see how anything can get past the HV fitter caps.
>>
>> KM1H also uses caps across diodes.  He also used another method, with a
>> .01uf cap across an entire series string of diodes, like a .01uf @ 5 kv
>> type.
>>
>> Orr's books recommend caps across diodes... to eliminate noise on TX on
>> ssb. .
>>
>> Are they required...or not ?
>>
>> Jim  VE7RF
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-- 
Thanks and 73, Jim W7RY