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.
This circuit is from a Popular Electronics from the 90's. It can be implemented with equivalent...
This two-transistor preamplifier was found in a 1960 Sylvania transistor manual. The output...
The gated oscillator shown here turns on when a “1" Iogic Ievel is applied to the input. The...