On Sun, 20 Nov 2011 22:07:02 -0600, "Lee K. Gleason"
wrote:

Hello all. I'm restoring an old radio, and in the process of replacing
the assorted electrolytic caps, I came across a half melted looking wax
coated cylindrical cap. The only markings on it are "Micamold 420E2503. On
the next line, it says ".05 plus or minus 20 150". It's a tubular shape, not
the usual postage stamp or lozenge shape that Micamold caps usually are.
It's got a band on one end, so I'm guessing it's polarized - although the
end without the band is grounded, the opposite of what I would have guessed.
I'm guessing, .05MFD, 150 volts. I can't just look it up in the schematic,
since this this part of the radio is a circuit a previous owner added on to
support a Magic Eye tuning indicator tube. What do you think?

From your description it sounds like a wax paper capacitor. The band
is not for electrical polarity but denotes which end is connected to
the outer foil, which was often connected to ground, assuming the
circuit allows, since that would then act like a 'shield'.

You should replace all the wax paper caps too, not just electrolytics,
because they fall apart, as you have noticed with that one.

Btw, you can't trust that the 'brick rectangle' ones are always mica
either. Micamold was notorious for making paper caps in that shape
(say, around 500pF or so and up) but others did it too.

..05uF, 150V sounds right.