I'm trying to find information on making paper capacitors. I want to make one just for fun, but I also want to try to make one that is like what you would find from the 50's.

I can't really find anything on how to make something commercial looking. A youtube video or 2 shows how to do it with regular tin-foil, but they are very large looking. Does anybody have any resource on what specifications on the materials they used?
It seems they used specific paper and foil. This video is actually really interesting about someone who manufactured capacitors, and he goes into some detail about what they used in paper capacitors, then goes into poly-propylene explanation.

http://www.youtube.com/watch?v=eY_9bKrcMpo

The closest I can come is the Pilot factory in the 1920s: I reprinted a 4-page article from the Pilot magazine Radio Design in vol.2, Radio Mfrs of the 1920s, pp.252-253. It has a few photos of the various operations.

I remember some Pilot capacitor material from Ghirardi's 1930 "Radio Physics Course". Might even be the same. Photo of a woman operating a winding machine, with an odd smile that looked like a retouch.

Dave Wise

You said a mouthful.

Yes, that's the one! It always gave me a creepy feeling, like maybe there was a dungeon under the plant.

Dave

I found a US manufacturer for foil and paper (but I do not know if they fill small orders - no prices means they probably sell giant orders business to business, but I'll email to find out)

Also, I thought, why not use a fishing reel for the winding mechanism? You can set the "tightness" of the paper being spun by the reel's pressure-knob, so it wont wind if you get to a certain pressure.

I would have to find a way to use the reel to wind a capacitor though, but it may be way easier than trying to keep the same pressure by hand.

I don't know what determines the voltage rating though. The number of times it is wound around?

Just for a little fun, I made a very very simple capacitor that worked ..... and I tested it in an AA5 radio from the vol control to the 1st audio ( just because it was an easy place to get at)
I forget the exact value.. maybe .005uf or so.

All I did was to use two sheets of aluminum foil about 6"x10" each and slipped a (sheet of paper) between them.
.. I used one page of a wide book .

Then I clipped an alligator lead to the edge of each piece of foil where it stuck out of the book.
I allowed one foil-edge to protrude at the top of the page, and the other foil-edge to stick out at the bottom so they wouldn't touch.

Then I connected the two leads in the circuit between the vol control and the grid of the 1st audio... worked fine.

Here is a less spooky version of the capacitor winding machine photo in the Pilot factory. This is a scan from Ghirardi's "Radio Physics Course" Copyrighted 1930, 31, 32. Both the hair and mouth of the lady look more normal in this photo. The photo in Alan's post must have been doctored for some reason.

Considering that the Radio Design photo is older, I'd assume it was altered for the later edition of the book. The new head is a profile, and doesn't quite match the body.

Yes, they didn't like her smile either, so they cut off her head and stuck on a ringer!

Dave