[Boatanchors] Polyester Capacitors in Johnson Ranger?

[WA5CAB at cs.com]

Mike,

You may have run into disinformation, which unfortunately is the Internet's 
primary product.  According to the Sangamo catalog sections in the 1960 and 
1963 Radio Master, the Type 33 is a molded paper dielectric capacitor.  The color 
is not mentioned, but memory says green.  The 1963 catalog lists a Type 33M, 
with mylar dielectric (mylar is a polyester), but it isn't in the 1960.  The 
molded case material is not actually given.  Sangamo called it "Humiditite".

The Sprague Black Beauties also used Mylar plus paper.  But the catalog entry 
also says they were impregnated with HCX.  Maybe that was their downfall.  
Had to read it twice to make sure it didn't say HBX, but fortunately only cannon 
cockers and Minemen would know what that is.

In a message dated 10/11/2008 12:04:05 AM Central Daylight Time, 
mharmon at att.net writes: 
> Anyway, I was inventorying the caps with the intent to replace them, and 
> I noticed a number of turquoise axial lead caps which were marked 
> Sangamo Type 33.  I did some research and found that these are polyester 
> caps.  The solder jobs look professional, but I thought polyester caps 
> came along well after the late Fifties when the Ranger was built (yes, 
> it was a factory job - all rivets).  In the early Sixties I was a high 
> school kid with a terminal case of screwdriver-itis.  The TV repairman 
> used to bring old chassis by the house and unload them for me to 
> cannibalize, much to the chagrin of my mom!  The only kind of caps I 
> remember seeing back then were molded micas, disk ceramics, nasty, 
> dripping wax-paper caps, and a lot of black beauties, which were a 
> sealed wax paper, foil, and oil abomination.
> 
> Could these caps be OEM?  Were polyester caps available back in the late 
> Fifties?  If so, they couldn't have been cheap.  If Johnson engineers 
> put them in their transmitters at the factory, the company must have 
> believed that they were worth the extra cost.
> 

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480


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