[ARC5] Mica Capacitor

[Glenn Little WB4UIV]

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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-- 
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Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)  USSVI LM   NRA LM   SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
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