We found this circuit in a 1964 Electronic Design. It divides the frequency of a 20 MHz signal by 2. The circuit uses a transistor from that time. Details of the coils were not given.
Suitable for recovering tape recorded media from a common tape player mechanism, this circuit is...
This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL...
This circuit lets through the 300 Hz to 3kHz range that corresponds to the human voice. We found it...