This anti-theft circuit was found in a 1985 documentation. It uses common components that can still be found easily. The relay is 12 V and the circuit has timings of 3 minutes and 20 seconds.
Found in a November 1977 Radio Electronics magazine, this digital circuit was described in an...
This powerful transmitter for the 27 MHz band was found in a Japanese publication from 1961. The...
This circuit was found in Radio Electronics magazine from April 1961. The device has a slot for...