The transistors of this circuit found in an English 1980s documentation may be the modern BC548 equivalents. The circuit is battery powered and the earphone must be crystal.
The circuit shown is from the Linear Applications Handbook and the maximum frequency is in the...
This 100 kHz crystal oscillator uses 7404 to generate square signals. We found it in a Popular...
The circuit shown is a reference of -10 V with a maximum current of 50 mA obtained from the Linear...