[Amps] door knob capacitors

[Rob Atkinson]

I'm looking at those doorknob caps for sale from Ameritron.  Actually
they are listed as MFJ but it's all the same now.

They have two types:

500 pF 7.5 KV and 170 pF 7.5 KV.  They are made by High Energy (type
HE50) and sell for $22 each from MFJ.   I wanted more information
about their current rating v. frequency so I went to the HE website
and found this data page:

http://highenergycorp.thomasnet-navigator.com/viewitems/ht50-ht58-series-ceramic-capacitors/ht50-series-ceramic-capacitors?

For the 170 pF cap the fL and fH give me some confidence but as value
goes up, frequency range lessens so one has to de-rate the current
capability for the high-bands.  but for load cap padders for a ham amp
even the 500 pF is probably okay at 30 MHz.  I'm still sticking with
what I have on hand for now though, my 2 buck micas because I am a
cheap ham.

Rob
K5UJ

On Sat, Mar 5, 2011 at 11:06 AM, Carl <km1h at jeremy.mv.com> wrote:
> Those are Teflon and not mica.
>
> Ive been looking for the manufacturer.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- From: "Rob Atkinson" <ranchorobbo at gmail.com>
> To: <amps at contesting.com>
> Sent: Friday, March 04, 2011 4:14 PM
> Subject: Re: [Amps] door knob capacitors
>
>
> okay, Genn; Hi Bill, I know about Ameritron but I usually forget to
> consider them, thanks. for the reminder.  I will take a look at what
> they have.
>
> 73
>
> Rob
> K5UJ
>
>
> Why don't you just order what you need from Ameritron? They have mica
> loading padder caps @ reasonable prices. That goes for any part from any amp
> they make.
>
> (((73)))
> Phil, K5PC
>
>
>
> On Fri, Mar 4, 2011 at 11:05 AM, Glen Zook <gzook at yahoo.com> wrote:
>>
>> No problem! My topic was finished a couple of days ago.
>>
>> Glen, K9STH
>>
>> Website: http://k9sth.com
>