[ARC5] Mica Capacitor

[Richard Knoppow]

     The only Micamolds I have encountered recently were the flat paper 
kind. The windings are actually quite neat as opposed to the Black 
Beauties I've dissected that were seriously deformed. The Micamold caps 
were somewhat leaky and high DF but I expect this of a sixty year old 
paper caps.

On 9/18/2016 3:53 PM, Glenn Little WB4UIV wrote:
> I have recently disassembled some of the flat, squarish Micamold
> capacitors.
> These were NOS, never soldered to.
> The pink, reddish cased ones were silver deposited on the mica sheets.
> The tan, yellowish ones were, what appeared to be aluminum ( I am not a
> chemist) sheets sandwiched between mica sheets.
> I all cases these all read low, out of spec, in value.
> I think that this is due to the case not providing as much pressure  and
> compression on the plates as when new (fresh).
>
> Has anyone else noticed these trends in value?
>
> Are all pink cased mica mold capacitors silver and yellow cased aluminum.
>
> These all had the first dot as black indicating JAN mica.
>
> 73
> Glenn
> WB4UIV
> On 9/18/2016 5:53 PM, WA5CAB--- via ARC5 wrote:
>> In a message dated 09/18/2016 16:12:03 PM Central Daylight Time,
>> 1oldlens1 at ix.netcom.com writes:
>>>      Micamold was a brand name. The company made several types of caps
>>> including real mica caps but is best known for the flat paper ones.
>>
>>
>> That's probably true today ("...is best known for...") but wasn't true
>> back when they were in business.
>>
>>>      I had not heard that early polystyrene caps had problems but can
>>> believe the cases got leaky.  Cracking at the lead entry is a problem
>>> with dipped caps even now.
>>
>>
>> Cracking at the lead entry point is one of the reasons that I have
>> always hated Orange Drops. When used as the designer intended (on PC
>> boards), there wasn't generally any cracking problem at least in
>> non-vehicular or aircraft equipment.
>>
>>
>> Robert Downs - Houston
>> wa5cab dot com (Web Store)
>> MVPA 9480
>>
>>
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>

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL