Leaking film caps

[dynaman]

What's an acceptable amount of DC leakage for a plate coupling cap? I've been checking by measuring DC voltage from ground to the "out" side of the cap. The few that I've tried all seem to hover around 200-500mV. Too much? Am I measuring incorrectly?

[Nigel Tufnel]

Desolder the "out" lead of the cap (the one without dc) from the circuit, then measure just as you were. Should be nothing or next to nothing in mv.

[dynaman]

Huh. Just tried it and the meter is jumping all over the place.

[selloutrr]

the voltage enters the possitive side of the cap. unsolder the negative lead, isolate it from other components and ground. set your multi meter to dc voltage. place the black test lead to ground and meter the red capacitor ground leg with the red test lead. the meter should read "0" volts dc or a very small amount of mili volt dc current. def under 1 volt of dc current. if you are having trouble getting a stable reading. try using alligator clips to secure your test probes to the the leads and ground. clip one end to the the test lead and the other to the part you are testing then you are hands free while testing. becareful while working with live voltage.

hope it helps stabilize your readings.