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.
The voltage gain of this DC amplifier is 100 times, given by the relationship between R2 and R1....
Here is a very useful circuit suggested by ICOTRON (Siemens) capable of eliminating the...
This circuit, suggested by Texas Instruments, is based on the integrated TL497A, designed for...