Eighty years ago, the May 1944 issue of Popular Mechanics showed how to put together this two-tube home telephone system. Both the master and remote units were built breadboard-style. It might have looked austere, but there was a war going on, and a metal cabinet would have been an unnecessary luxury. It ran off the AC line, and the filament voltage was obtained by dropping it through a 40 watt light bulb. Calling was accomplished by an independent bell or buzzer. Therefore, it could be switched off until needed.

This couple were using it to communicate from house to barn. But the magazine noted that it could be used to communicate with the photographic dark room, since the remote emitted no light.

All parts could be found in the proverbial junk box, or from the dime store. For example, the talk-listen switch is fashioned from the handle of a toothbrush.