This circuit was found in a 1970 US publication. Transistors are still common and the circuit can be used as a PWM shield or pulse transmission modulator.
Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally...
This circuit is from Radio Electronics. The magazine no more exists, but the circuit can be...
An oscillator that uses two gates is not suitable for critical applications, as it tends to pick...