Found in a 1964 Electronic Design this circuit compares two signals by providing the inverse of the algebraic sum of their frequencies. The circuit can be made with modern equivalent transistors.
This 1.5 A source for FM transmitters was originally intended for the transmitter described in...
This circuit protects power supply equipment against transients coming from the power line as well as...
The power source shown for powering for small TTL circuits was found on a Radio Electronics...