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 based on an uncommon Texas component today, as found in an American 1980s...
This circuit is from the 80's documentation. The integrated circuit is from the time but can be...
In the figure we have a configuration that allows to test NPN transistors and with the addition of a...