This circuit was found in Radio Electronics from the 90s. The sensor is an oscillator whose frequency depends on humidity, an uncommon component nowadays.
This RF amplifier step has a dynamic range of 140 dB and can amplify signals from 0.5 to 40 MHz....
This circuit is from an old English documentation. It is intended for coupling a microphone to the...
This circuit was found in a Radio Electronics magazine from October 1987. It can be used as a...