Suggested by a 1990 book for amateurs, this circuit makes use of an integrated component that is not common today. It converts signals from one band to signals in a 10.7 MHz band below.
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...