Found in American documentation from 1969, this circuit uses logic inverters to obtain sequences of 4 pulses. The circuit can be used as a shield.
Found in a 1958’s publication, this receiver uses components that are nbot easy to find in our...
This car battery power supply was found in the June 1990 issue of Radio Electronics magazine....
This circuit, found in documentation from the 1980s, uses an operational amplifier from that time....