Hi- I have some kind of old tube tester thing I bought on ebay. It has 3 guages- mA , Volts AC, and Volts DC. There is a 4 prong tube socket on it, and a wire with a 4 prong tube plug. Theres 2 buttons and a 10 pos switch. It looks like maybe you plug a tube in the socket, and plug the plug into where the tube came from in a battery set. The internal wiring is the same type as in my old battery set from the 20's. Any ideas what it's for ? There is a pic up on my site www.infoblvd.net/landerr/index.htm I've drawn the schematic for it, but I'm still confused as to its purpose. Thanks for any help. I can post the schematic or pics of the inside if it might help. Ryan

Also- I forgot to mention the terminals to hook to are labled B+amp, B-batt, A+, and A-. there are 5 more that arent labled.... There is also two adapters that go from 4 prong to 5 prong... one for the socket, and one for the plug. Thanks again for any light you might shed ! Ryan

Hi Ryan

From your description it's a tube tester from around 1926. By 1927 the 5 pin , #27, was available. So it would have needed an adapter.

"A" battery are filament leads. "B" battery is for the plate supply.

Norm

: Also- I forgot to mention the terminals to hook to are labled B+amp, B-batt, A+, and A-. there are 5 more that arent labled.... There is also two adapters that go from 4 prong to 5 prong... one for the socket, and one for the plug. Thanks again for any light you might shed ! Ryan

That's a set analyzer, 1927-28 (since it has a five-pin socket and an AC meter). You were correct, you plug the analyzer into the radio and the tube into the analyzer. Sort of an extension cord for the tube. Then you can measure voltages and currents without having to pull the chassis from the cabinet. These were popular for a few years.