Schmitt Trigger 7400 (CB22419E)

This low hysteresis circuit was obtained from old documentation. The circuit must be powered by a voltage of 5 V.

Fire alarm (CB7240E)
This 1968 Mullard circuit detects fire by smoke using LDR-type sensors. The circuit makes use of...
Crystal test (CB7538E)
Found in the American 73 magazine for radio amateurs, this circuit can test common quartz...
50 MHz Converter (CB20254E)
With this circuit it is possible to tune the signals in the 50 MHz band in a common AM receiver around...