We have many tube tester circuits in this section. This one came out on a Radio Electronics from 1949 and has a very elaborate configuration with toggle switches.
This circuit, from a 1990 documentation, can serve as a basis for a game of target-game. The...
While BC547 is not a suitable transistor, it can work on this circuit. The ideal would be the...
This power supply that we found in an old American documentation uses an integrated circuit that...