[Boatanchors] Testing Mica HV "Postage Stamp" Caps

Fri, 09 Apr 2004 11:05:45 -0400

Bill Pancake wrote:

> Need a little help to understand how to bench-test mica
> transmitting capacitors, the "postage stamp" variety...

No experts stepped forward, so I take a stab at this.

Step one:  Use an ohm meter.  Anything less than infinity, 
<40 megs on usual DVM's, is a problem.

Step two:  Connect one terminal of the cap-under-test to an 
HV power supply and the other to ground through a 1-meg 
resistor.  Measure the voltage across the resistor with a 
VTVM or DVM.  It will be approximately one volt per microamp 
of leakage.  I'd expect the leakage of a good cap to be 
almost unmeasurable.

Al

-- 
Al Klase - N3FRQ
[email protected]
Flemington, NJ 08822
Web Page:  http://www.webex.net/~skywaves/home.htm