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 with germanium transistors was found in documentation from the 50's. The transistors are...
The circuit presented was found in a documentation from the 1950s, generating a sinusoidal signal...
This circuit was originally indicated as a signal reinforcement step for the previous receiver...