We found this circuit in an Electronic Design. The main integrated circuit is the 4017. The frequencies are determined by the RC circuits as well as the duration of the generated pulse train.
This sensitive receiver with earphone was found in an English documentation from 1963. The...
This is a classic FM amplifier IF amplification stage configuration. The circuit is from a 1980s...
This circuit was taken from an article in Electronics Now magazine in February 1995. The power...