This circuit with three transistors was suggested in a Radio Electronics magazine from February 1963. The transistors are types of the time. Power comes from a 12 V battery.
This circuit was obtained in a 1977 magazine, but it can still be easily assembled, as the...
This intercom for the 27 MHz band was found in a recent English documentation, working with a...
This relay shield circuit for old computers was found in January 1983 Radio Electronics magazine. The...