This circuit divides the frequency of a 2 kHz signal by 2. The circuit was found in Philips documentation from 1964. Modern transistors can be used for higher frequencies.
This circuit uses a Hall device from that time as a sensor. The circuit is from an English...
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This audio generator that produces both rectangular and sinusoidal signals was found in a...