This circuit is from an Electronics World of 1967. The described calculations can be applied to equivalent circuits with modern transistors.
The resonant circuit depends on the crystal frequency that can go up to a few megahertz. The...
This switched amplifier or PWM was obtained from a 1972 RCA technical documentation, using...
This circuit for a frequency of 10 kHz was found in an Electronic Design. It makes use of a tunnel...