Lane,
I have just plain scrounged them over the past 40 years. Sorry--I know it's
a cop out. Rich, yes, I have used only micas on 160 meters in plate tuning
rated at 8-amps. Lesser current in the PI-L output side.
73, K6XK
-----Original Message-----
From: zeitler@ibm.net <zeitler@ibm.net>
To: Roy Koeppe <royanjoy@ncn.net>
To: <amps@contesting.com>
Date: Sunday, January 24, 1999 2:56 PM
Subject: Re: [AMPS] Re: Ceramic Caps in PA Tanks
>What is your source for the micas? Rf Parts?
>
>Lane
>Ku7i
>-----Original Message-----
>From: Roy Koeppe <royanjoy@ncn.net>
>To: amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
>Date: Sunday, January 24, 1999 7:17 AM
>Subject: [AMPS] Re: Ceramic Caps in PA Tanks
>
>
>>
>>Hi Bill,
>>
>>Well, I experimented long and hard, testing even high-grade xmitting
>>ceramics in the plate tuning and loading locations. They all drifted to an
>>unacceptable degree. I presume from the tube heat alone.
>>
>>So, have sworn them all off. Big micas rated 8-amps do the trick. They
>don't
>>budge one iota! Lesser current ratings are OK in the loading section, but
>>still need to be micas.
>>
>>Good investigating & 73, K6XK
>>
>>-----Original Message-----
>>From: WB6WCW@aol.com <WB6WCW@aol.com>
>>To: royanjoy@ncn.net <royanjoy@ncn.net>
To: <amps@contesting.com>
>>Date: Saturday, January 23, 1999 7:26 PM
>>Subject: Re: [AMPS] To Ten-Tec Inc, et al, Re: Titan II
>>
>>
>>>Hi Roy:
>>>
>>>My experience in fixing-up an Amp Supply LK-550,
>>>which uses (3) 3-500Z tubes, is that the 'padding'
>>>capacitors get quite hot on 80 and 160.
>>>
>>>I believe it is due more to a misuse of the parts, than the fact
>>>that they are ceramics.
>>>
>>>If you look at <http://www.rfparts.com>, under "Products", look
>>>at "Ceramic Bathtub" capacitors. It lists the current ratings
>>>of the HT-50/HH58/850S family of capacitors. At 1 MHz, the
>>>1000 pf caps are only good for 1.6 amps (and they do overheat).
>>>
>>>If you replace the 1000 pf with a pair of 500 pf caps, then the current
>>>rating is 6.4 amps (and will not overheat). Carl (KM1H) recommended
>>>that I use 750 pf units, it would require less parts (cheaper), but
>haven't
>>>been able to find any of them.....
>>>
>>>After fixing all of the "Tune" padding capacitors, I still had a problem
>>>on 160 mtrs with the ceramics they used on the output side of the
>>>pi-network. Same problem; 1000 pf capacitors overheating. Am
>>>presently replacing them with 500 pf units-----and I sure hope that
>>>solves the final problem (it's getting rather expensive).
>>>
>>>Good Luck & 73's
>>>
>>>Bill W6WCW (E-Mail: WB6WCW@aol.com)
>>>Santa Barbara, CA.
>>>
>>
>>
>>--
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>>Problems: owner-amps@contesting.com
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>>
>>
>
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