This sequential tone generator circuit was found in the July 1980 issue of Radio Electronics magazine. It uses well-known integrated circuits. The tones are generated by programming resistors.
Found in American documentation this circuit uses transistors of the time. The circuit can be made...
This flasher with two power transistors was found in a Radio Electronics magazine from September 1961....
Found in American documentation from 1969, this circuit switches signals with a FET of the time....