[Hallicrafters] SX-101A selectivity

[Dave Moorman]

on 2/17/02 10:22 AM, F W Mooney at fmooney at sprintmail.com wrote:

> What value were the caps?  In my re-capping adventures, I've found that the
> smaller caps, the picofarad varieties, hardly ever need replacing, while the
> larger ones do.  I recapped an entire S-40A recently, and found that every cap
> marked in the picofarad range (uuf on old schematics) actually were still in
> range once I took them out and measured them.  I was about to come to the
> conclusion that the smaller caps can be left in.
> 
> - Fred
> 
> ----------

That's typically true, Fred.  The smaller value (and size) caps are usually
ceramic or mica and don't deteriorate like the larger ones.  The larger
value and size ones are paper caps.  They're tubular in shape are often
"black beauties", which are black with the capacitance color-coded on them,
or "Tiny Chief" or other brands.  After 40 or 50 years they become more like
resistors than caps.

Usually you can leave the smaller caps in with no ill effects.


Dave