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 was found in a 1977 Radio Handbook. The ports used are CMOS like 4001 and the...
I found this Vox circuit or acoustic receiver as it was originally called, in a 1973 publication. The...
Found in RCA documentation from the 90s, this bass and treble control uses an operational...