gil wrote:
I always heard about leaky caps being a problem with boatanchors, other than
checking for the capacitor value is there a way to check if its a "leaky
cap" using just a multitester or voltmeter?

Thanks.....gil


There's some good capacitor testers around but as a rule on older BAs
(30s-40s) if it doesn't pass an ohmmeter test you need not go any
further. I chuck anything over about 1 Meg of leakage which tends to be
most all wax/paper caps from that era.
The digital voltmeters often have a capacitance test function but are
thrown off in the presence of leakage. Again, if it doesn't measure
right, out she goes.
The problem is due to the breakdown of the paper dielectric inside. For
the most part thats inevitable in spite of how well sealed it is. Some
of the high-end mil-spec metal cased guys have survived but thats about
all. The rest are hit-and-miss.
In later gear, say the 50s, the "good" rate is much improved but certain
types like the banded black beauties are notoriously bad as are those
pink plastic ones found in 50s/60s Hallicrafters gear.
The debate lingers on just how much performance degradation and
reliability can be tolerated since the bad caps may not have a
particular detrimental effect *today* depending on where in the circuit
they are used. I suppose it depends whether or not you are "restoring"
or "repairing".
I cross-posted this to rec.antiques.radio+phono so you could catch some
other opinions.
Good luck!
-Bill