Testing Phono Cartridges

Without knowing more about the phonograph, I can't say.
Ceramic cartridges are faily low voltage.
Magnetic cartridges are electromagnetic, and, have to have an extra pre-amp stage in order to work properly.
If it's a childs' rp, I guarantee it doesn't use a magnetic cartridge.
Bill Cahill

The 1947 Silvertone does humm when the positive lead is touched. When I touch the negative lead, the humm reduces. When I rub my finger across the positive lead, I get the scratch sound through the speaker. So, I would assume that my cartridge is bad. I put a meter to it on the 1K scale and it went up a little. I didn't get a reading off of it.

Meters cannot read cartridges, but, I guarantee the cartridge is bad.
You need a crystal cartridge, or, higher voltage ceramic.
How manny tubes in this set?
Bill Cahill

Without looking again I think it has 5 tubes. How much would it cost to rebuild the cartridge? Is it better to put a ceramic one in?

That would depend on the cartridge. Personally, I think it's better to get original re built.
There is a companny in Ohio that still does it.
Not sure of cost. Maybe 40.00 with needle, but, don't hold me to that.
Bill Cahill

I found a site that explains rebuilding by replacing the crystal with a piezo element from radio shack. The element is only $2.00, and will pick one up and try it out.

That sounds interesting, John. So what is the site? Let us know if you try it. I would like to try rebuilding one also if I could find a way to replace the crystal. I have about 8 players now that have bad cartridges so if you find a more economical way to do it that would be great.

I will post the site tomorrow when I can get at teh printout. I brought 2 piezos and took one apart. It looks like an easy fix.

http://www.angelfire.com/electronic2/radiosean/tv/Cartridge-rebuild.htm

Thanks for posting the web site. I will pickup one of these and try it.

I made mine a little bit bigger to eliminate resoldering. I will pot out the back end with silicone and solder the existing wires to the phono wires with heat shrink over the joints instead of using the bus pad. I assembled it last night and I will try it out tonight.

I tried to crimp the crystal holder down and I broke off one of the arms. I tried hot gluing the piezo to the arm. It held but the sound was very faint. The holder is aluminum so it does not take solder. I don't know what the function of size of the piezo would be to the amount of sound that It will generate.
If I can find a cartridge from a child's phonograph, that would be crystal?