The ZN416E integrated circuit is uncommon today. It consists of a complete radio, like the one found in a 90s Popular Electronics. The power is from a single battery.
This circuit is from a 1980s documentation, but the configuration can be applied to most modern...
This 0.5 Hz filter was found in the December 1990 issue of Radio Electronics magazine. The power...
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...