This powerful sound emitter used in defense to intimidate people was found in a 90s Popular Electronics. The circuit produces a strong modulated tone of 3 kHz. The modulation is 10 Hz.
The integrated circuit used in this small transmitter is not very common today. The coil has its...
We found this circuit that was part of a teaching set in a Radio Electronics magazine from June...
This signal amplifier for ATV in the 427 to 439 MHz band was found in a magazine 73 for radio...