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 circuit was found in documentation from Analog Devices from the 90s. The circuit uses...
I found this simple circuit from an English magazine from 1984. The circuit can be easily...
Found in a 1964 Electronic Design, this circuit generates pulses based on an avalanche diode of...