Found in an Electronic Design of 1964, this circuit is intended to the signal amplification in the 88 to 108 MHz band. The transistor can be a modern equivalent.
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...