This RF amplifier step has a dynamic range of 140 dB and can amplify signals from 0.5 to 40 MHz. FET is old, but modern equivalents can be used.
Found on a 1969 EDN this circuit switches a current from a digital control signal. The impedance...
The Toshiba TLP577x series consists of an infrared photo-emitter (IR) and a sensor integrated circuit...
This conventional 4 channel circuit with the 4017 and 555 was found in the November 1991 Radio...