This circuit was found in the July 1998 issue of Electronis Now magazine. It is a traditional gated version of the 4049 and has its frequency controlled by R2.
This Japanese radio is from the 60s, presenting excellent sensitivity and an output power of 100mW...
Found in a Popular Electronics from the 90s, this circuit uses components that are still current....
This circuit consists of a simple capacitance bridge. The handset can be high impedance from 500...