RF or even switching transistors like the 2N2222 can be used in this circuit. The capacitors are ceramic and the frequency is determined by the crystal.
This counterphase circuit is from a 1973 publication, and can work with mains voltages or 12 V....
This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose...
This basic 100 kHz oscillator is suitable for use in calibration. We found it in documentation from the...