This category may include non-commercial sites about vintage primitive radio sets, instructions for building replicas, and anecdotes about primitive or homemade clandestine radio listening devices. Crystal radio kits for sale should be submitted to Shopping/Consumer_Electronics/Communications/Wireless/Radios/Kits_and_Components.

Foxhole radios are simple radio receivers constructed from a minimum of materials, typically a razorblade, a safety pin, a coil of wire, and sometimes a short piece of pencil lead. These devices were made by soldiers in World War II for entertainment, or were operated clandestinely by prisoners.