[Amps] dual section cap

[MU 4CX250B]

Interesting, Carl. I don't understand why the minimum capacitance on
the small section is so high. I suppose I could remove a plate nearest
the frame of the capacitor, but I wouldn't think that would reduce the
minimum capacitance to 6 pF. How did you accomplish that?
73,
Jim W8ZR
Sent from my iPhone

> On Jun 25, 2014, at 7:20 PM, Carl <km1h at jeremy.mv.com> wrote:
>
> OK that explains it Jim, I thought you bought it with those markings on it.
>
> The poor response on the small section shows it wasnt designed for a good minimum capacitance which would be a problem on 10M with several tubes.
>
> I got one of those from OEP as a "sample", rebuilt it with a bit less C per section but 6pf min C on the small one, returned it, and had them make several runs for me of 10-20 at a time. They sold well.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- From: "Jim Garland" <4cx250b at miamioh.edu>
> To: "'Carl'" <km1h at jeremy.mv.com>; <amps at contesting.com>
> Sent: Wednesday, June 25, 2014 7:07 PM
> Subject: RE: [Amps] dual section cap
>
>
>> Carl,
>> I remeasured the cap, and the two sections are 17-63pF and 24-316 pF, pretty
>> much what I had measured before N years ago. A single section cap on the
>> same frame would be 379 pF, or maybe a smidgen more since there would be
>> coupling between two plates that are separated in the dual-section version.
>> I used a good quality cap meter and compensated for the lead capacitance.
>> 73,
>> Jim W8ZR
>>
>>> -----Original Message-----
>>> From: Carl [mailto:km1h at jeremy.mv.com]
>>> Sent: Wednesday, June 25, 2014 4:00 PM
>>> To: Jim Garland
>>> Subject: Re: [Amps] Buck-Boost Transformer Selection
>>>
>>> Jim, that OEP cap of yours got me looking and it appears that somebody
>> used
>>> the full value for that frame. IE; the Cardwell 154-10 is rated at 347pf
>> and
>>> that frame length was used for the dual section.
>>>
>>> Carl
>>> KM1H
>>
>>
>>
>>
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>