This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent components. The transistors may be BC558 and the transformer is obtained from a disused transistor radio.
This TTL siren is formed by two oscillators using each two Gates of a 7400. Frequency or the...
Depending on the components, given in the table, this circuit can amplify signals of 100 MHz or...
This circuit, which can be used as a shield, was found in old documentation. The circuit must be...