This is a field strength meter found in an 80's Hands On. The circuit operates at frequencies up to 500 MHz and has a buzzer as its indicator. Can be used as a detector for spy transmitters.
This compact power supply can be used on the workbench for up to 1 A load. The transformer has 1 A secondary...
This amplifier with an OTA has a gain of 40 dB. The power supply must be symmetrical. Found in...
This circuit was published in an English magazine from 1980. The magazine no longer exists, but...