The plans for this crystal set appeared 80 years ago this month in the January 1941 issue of Popular Mechanics. Laying out a circuit in this manner is often called “breadboarding,” and this picture shows why.  The chassis for the set was a literal breadboard.

In addition to serving as a radio, the set could also be used as a piece of test equipment.  It had terminals for incoming AF or RF, and could be used as a signal tracer to troubleshoot other radios.