This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The transistor admits equivalent as 2N2222 or BF494. The circuit is from an old American publication.
Found in a 1975 radio amateur publication, this simple oscillator is for code practice. The PNP...
This experimental flip-flip changes its state by the command of two push-buttons. The state is...
This high selectivity circuit for single tone decoding was found in 1970s documentation. The coil...