This two-tone alarm siren was found in the January 1975 issue of Radio Electronics magazine. The power transistor can be changed and with it, Rx has values from 10 to 47-ohm.
This transmitter is modulates a infrared light source from an audio signal. Applications include a...
This turntable filter was found on an 80's Elektor. The circuit makes use of operational features...
This circuit is from a Radio Electronics magazine from May 1989. The power supply must be...