This woman, like most radio listeners 85 years ago, knew that a good crystal set would pull in local stations with ample volume and excellent tone, as long as an antenna and ground were available. She took advantage of this knowledge and constructed the low-cost (under a dollar) pocket size crystal set with built-in headphone. The antenna and ground leads had clips on the end, so it was an easy matter to clip it to a telephone, as she did here, or even to a metal drain pipe or water pipe.

As long as the building was not of metal construction, this was said to pull in stations from 2-12 miles away. At home with a long outside antenna, receptions of powerful stations 30 miles away was possible.

The design is from the June 1939 issue of Popular Mechanics.