Found in an old Radio Electronics, this circuit applies to frequency meters for frequencies up to 100 MHz. The input impedance is in the order of 1 M ohm.
This circuit converts inductances on two scales into voltages. The circuit was obtained from a...
Placed in the vicinity of a telegraphic transmitter (CW), this circuit produces an audible signal on...
This circuit was found in a 1967 RCA documentation. The components are of the time. The circuit...