[ARC5] Mica Capacitor

[Sandy]

This is the "gospel truth"!  Ask the real old timers who dealt with 
"Moulded paper" (alias: MICAMOULD) capacitors!  absolute trash, short 
shelf life.  Anyone who has "recapped" an old SCR-522 transceiver or 
some BC-312, BC-342, BC-348 receivers will attest to this.  Drove 
SCR-522 radio rebuilders nuts.  Even on brand new unused gear!

73,

Sandy W5TVW


On 9/17/2016 2:36 PM, Richard Knoppow wrote:
>    A note: The charts will show a color dot on some flat type caps 
> which is either white or silver,  or black. Black is for mica, white 
> or silver for paper. One may encounter flat paper caps in some older 
> equipment, they were made by Micamold and Solar, maybe others. They 
> should replaced. They may have been high performance when new but 
> suffer from the same ageing problems as other paper caps.  They were 
> sometimes used in place of mica caps in less critical applications 
> during WW-2 when mica was in short supply.  Plastic film caps are good 
> replacements and probably superior to the originals when they were new.
>
> On 9/17/2016 12:10 PM, WA5CAB--- via ARC5 wrote:
>> Those charts are in most of the TM 11's printed from 1942 or 43 into the
>> mid-1950's.
>>
>> Robert Downs - Houston
>> wa5cab dot com (Web Store)
>> MVPA 9480
>>
>> In a message dated 09/17/2016 10:44:17 AM Central Daylight Time,
>> releazer at earthlink.net writes:
>>> Ken:
>>>
>>> Okay, I found the mica cap color codes in a copy of TM11-630. I had
>>> no idea
>>> there were so many kinds.  Anyway, I decided that the codes on the
>>> mica cap
>>> matched the American War Standard, and equate to 0.01 mfd bypass cap,
>>> 500V.
>>> It's not too hard to find a ceramic disk cap with those values!
>>>
>>> By the way, I scanned the cap color code section out of that TM and if
>>> any
>>> one wants a copy I can e-mail it to you.
>>>
>>> Thanks!
>>>
>>> Wayne
>>
>>
>>
>>
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>