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[AMPS] Rf high current caps for sale in Finland

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Subject: [AMPS] Rf high current caps for sale in Finland
From: (sm5ki)
Date: Mon, 31 Jul 2000 13:48:53 +0200
I have just returned from the Finnish Ham Summer Camp: Markku from was there and he has a lot of Russian condensers to be used,
as I believe, in tank circuits. Check with him.

de Hans SM5KI
>Från: "Tom Rauch" <>
>Till: "Phil Clements" <>, "\"AMPS\"
<>easures" <>
>Ämne: Re: [AMPS] Caveat on Dentron Filaments + MLA-2500B Notes
>Datum: sön 30 jul 2000 13.44

>> >?  The MLA commits one of the worst layout errors known --too much
>> >distance between the anodes and the Tune-C
>> >
>> >You have got to be kidding! The distance is 5 inches..
>5 inches is a long distance, unless there is no other option.
>> >The other day you mentioned Alpha 77SX's using non-RF rated padding
>> >caps...I have had several SX's and repaired several. They all use RF
>> >rated door knob caps.
>> ?  RF rated caps come in two flavors, for use in tanks (-750ppm) , and for
>> bypass use.  Bypass caps are not suitable for use in tuned circuits.
>Transmitting doorknobs are all RF rated. The temperature
>coefficient is a offshoot of the amount of capacitance and voltage
>At about 200 pF and 5 kV a single-layer ceramic capacitor is
>forced into the next higher range of N3300. The greater the
>capacitance, the higher the temp coef.
>Below 200 pF, you can normally purchase N-750 and at very low
>values NPO types. None of this has anything to do with the
>capacitor being a "bypass type".
>> > The trouble is that the 5 kw output is too much for the 160m
>> >load padders and they get hot and drift.
>> ?  ...  tank circulating current with two 8877s is about 20A.  The 160m
>> padder cap that is used is rated at 1.4a max @1MHz.
>The padder cap gets a portion of the current, and the current rating
>increases with frequency. The rating is also only for a given
>temperature rise, and can be substantially increased if the
>capacitor is mounted to heat-disippating surfaces and if the
>capacitor drift is not a problem.
>The ratings explanations in the Jennings/HEC catalog cover all of
>73, Tom W8JI
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