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 the 1974 Ferranti transistor manual, this Schmitt trigger circuit uses general-purpose transistors...
This circuit was developed to test suspect 4001 and 4011 integrated circuits. The circuit is from...
This power source with silicon diodes at a time when valves were still used was found in Radio...