1920s battery radios....how do they work?

[Kevin Kuehn]

Originally Posted by Kamakiri

Incidentally, I started figuring out how to tune them by hooking up a signal generator and dialing them in with it, then cutting the power when I found the desired frequency. Since all of these radios seem to love being hooked up to the signal generator and get much better reception when hooked up to it even when it's off, until I get a larger antenna I just run them that way

Any insights and advice are always appreciated!

The signal generator is probably acting as a coupling devise to your homes AC wiring, which is acting as a makeshift long wire antenna. The down side to using your homes wiring is that the radio will hear all kinds electrical noises riding on the power line. Even the ground wire to your homes electrical system may act as an antenna at radio frequencies.