[Hallicrafters] reading caps...

[Mike Everette]

There are several, I think at least three, different
color code schemes for the flat molded capacitors
which are either paper or mica types.  The best place
to find information is in older ARRL handbooks from
the 50s and early to mid 60s.  It can be very
confusing unless you have access to each of the codes,
because otherwise you may not be able to determine for
sure exactly what you're dealing with.  

For example, if you read the code wrong, or use the
wrong code to begin with (easy to do), you may not
only misread the value of the cap, but mistake a mica
for a molded paper.

At least one of these old handbooks should be a
required text on the list of everyone who does radio
restoration, and not just for all those great old ads.

These books are not expensive, typically from $5 to
%10 at hamfests, and can often be found on that place
we cannot mention. Look for anything from about 1950
to 1965, because these will cover the JAN (Joint Army
Navy) color code scheme which emerged from World War
II.  Handbooks from prior to 1950 may not yet have
been revised to include the JAN code, so check to see
if it is there.  You need that information.

A lot of surplus caps found their way into
commercial/consumer radio production after the war. 
Manufacturers snapped them up because they were good
quality and CHEAP.  They sometimes got intermixed with
non-surplus, so you may find more than one color code
used on the caps in any given piece of gear.  And
there are two versions of the "civilian" EIA/RMA
codes, which these handbooks also cover.

These books also show how to read the color-dot codes
used on older disc ceramic caps.

73

Mike
WA4DLF


		
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