Use the oil filled cap. Oil filled caps unlike electrolytics do
not dry out over time and break down. Usually electrolytics are
used because they are usually cheaper than a comparable oil
filled unit (new). Unlike grid bias supplies, the plate supply can
tolerate a certain amount of ripple and everything will still
be OK. The oil filled unit also won't require voltage equalizing
resistors across it.
Keep one hand in your pocket!
Later,
Walter
At 06:59 PM 2/3/98 +0000, you wrote:
>I have a question on HV power supply caps. I'm building a power supply for
>about 2500v at an amp or so to power some VHF amplifiers. I have an oil
>filled cap that's rated at 35 uf at 4500 V. I was thinking of using this
>cap, seeing it's similar to the cap used in the ARRL handbook for the
>3CX1200 amp. I have heard two conflicing ideas about this -
>
>1. Great idea, that's what most supplies would use except they're too
>expensive. If you have one surplus go for it.
>
>2. These are made for low ripple applications and you're better off going
>for a string of electrolytics with a good ripple rating.
>
>Has anybody had experience using a cap like this one. I used something
>similar years ago, but then again I used 6CW4's on 432 then also.
>
>Frank
>W2FCA
>
>
>
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