Have been looking for some time for a Jackson 591 capacitor tester. I learned of these from the great instructional videos put out by Paul Carlson (google "Mr. Carlson's Lab"). While digital capacitance meters are readily available, what they can't do is check for leakage, and it seems that's where most of these old caps fall short.

Finally acquired one, and just replaced its capacitors, so what is the first thing to do? Obviously test the old caps removed from the 591. Here's a rather poor, dark video, but I wanted the "magic eye" to stand out. The cap I'm testing is rated for 600 volts. I tested at 6 volts, followed by 20, 100 and then 200 volts. Notice the eye doesn't open at all at 200 volts. Yup, that's a leaker!

http://vid195.photobucket.com/albums/z238/JustJimPix/5912_zpsq6x214hg.mp4

The unit also tests capacitance, and while I didn't buy it for that function, it's amazingly accurate. Sometimes old tech is good tech!

BTW: I don't have a manual for this, and I don't quite understand the "power factor" control. Anyone know the function of this?

Cheers...   Jim

Not sure of the exact formula and too lazy to look it up, but Power Factor is a ratio of capacitive reactance and leakage/internal resistance.

Thanks Frank-

That helps, I'll do some research.  Jim...

If the power factor control works the same as on my Heathkit C-3 bridge, it's worked along with the capacity control for maximum deflection of the magic eye tube. It's like tuning a Pi Network final.

Thanks again, Frank!

I grabbed a manual for that Heath and read through it. I think I have a grasp on it now.    Jim...