This EBay item number has a large amount of info about it... 270766657819
73
Jim W7RY
--------------------------------------------------
From: "Mitch Cox" <ww4cox@embarqmail.com>
Sent: Sunday, June 19, 2011 1:28 PM
To: "Pete Raymond" <n4kwpete@centurylink.net>; "Vic K2VCO"
<vic@rakefet.com>; "Paul Kraemer" <elespe@lisco.com>
Cc: "Amps reflector" <amps@contesting.com>
Subject: Re: [Amps] Using an oil capacitor
> Yours does not sound like a photo-flash or pulse rated capacitor. You
> should be good to go with that one. All of the conversation so far has
> been about pulse rated as opposed to capacitors like yours that is rated
> for continuous service.
> ----- Original Message -----
> From: Pete Raymond
> To: Vic K2VCO ; Paul Kraemer
> Cc: Amps reflector
> Sent: Sunday, June 19, 2011 4:12 PM
> Subject: Re: [Amps] Using an oil capacitor
>
>
> I have been following this thread with some concern. My oil filled
> capacitor measures
> 4 3/4" X 4 1/2" X 9 1/4", its markings are as follows. General Electric,
> Capacitor, Made in U.S.A.,
> 25F492, 25uf at 4000 VDC. How can one tell if this capacitor is suitable
> for a HV power supply.
> 73 Pete, N4KW
>
> ----- Original Message -----
> From: "Vic K2VCO" <vic@rakefet.com>
> To: "Paul Kraemer" <elespe@lisco.com>
> Cc: "Amps reflector" <amps@contesting.com>
> Sent: Sunday, June 19, 2011 1:34 PM
> Subject: Re: [Amps] Using an oil capacitor
>
>
> > Several respondents to my message have said the same thing. This
> capacitor
> > cannot be used
> > at its voltage rating in filter service and needs to be de-rated to
> about
> > half its spec'd
> > voltage in that case.
> >
> > I actually have two of these, so I could probably use them in series
> for a
> > 26.5 uf filter
> > capacitor. This would be adequate for a cw transmitter, although I'm
> not
> > sure if 6% ripple
> > wouldn't be audible on SSB. However, two capacitors make a very big
> > package, so I'm
> > thinking about going back to the conventional string of electrolytics.
> >
> > Any recommendations for a source of electrolytics? There are lots of
> > inexpensive ones on
> > ebay, but who knows if they are factory rejects!
> >
> > On 6/19/2011 10:10 AM, Paul Kraemer wrote:
> >> Vic BE CAREFUL. BE VERY CAREFUL!!!
> >> From the size and capacitance you describe it is probably an "energy
> >> storage capacitor"
> >> which is not suitable for power supply filter at even it's published
> >> ratings. You will be
> >> picking pieces of capacitor out of places you really don't want them.
> >> Paul K0UYA
> >>
> >> ----- Original Message ----- From: "Vic K2VCO" <vic@rakefet.com>
> >> To: "Amps reflector" <amps@contesting.com>
> >> Sent: Sunday, June 19, 2011 12:59 AM
> >> Subject: [Amps] Using an oil capacitor
> >>
> >>
> >>> I have an oil capacitor rated at 53 uf 3.5kv. I would like to use it
> in
> >>> a power supply
> >>> with a transformer delivering 2.4 kVAC. The peak voltage is thus
> close
> >>> to 3400V.
> >>>
> >>> I've never used an oil capacitor before. My line voltage is pretty
> >>> constant at 240V, but
> >>> if it were to rise to 250V, the voltage rating of the capacitor would
> be
> >>> exceeded. What
> >>> kind of safety factor do capacitors like this have?
> >>>
> >>> The capacitor is 4-1/2" x 4" x 10" and is marked CSI 4W308T. The CSI
> >>> website
> >>> <http://www.csicapacitors.com/csite/cms/149.htm> doesn't list this
> >>> particular one, but
> >>> other 3.5kV capacitors have similar part numbers. There's no detailed
> >>> spec. There is this
> >>> statement:
> >>>
> >>> "The WM series of capacitors is designed for general purpose pulse
> >>> applications in power
> >>> supplies for lasers, flash tubes and other capacitor discharge
> circuits
> >>> where moderate to
> >>> long life is required."
> >>>
> >>> I'm not sure if this is appropriate for power supply filter
> application.
> >>> Anybody familiar
> >>> with these?
> >>> --
> >>> Vic, K2VCO
> >>> Fresno CA
> >>> http://www.qsl.net/k2vco/
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >
> > --
> > Vic, K2VCO
> > Fresno CA
> > http://www.qsl.net/k2vco/
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
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