Found in old documentation, this circuit can use modern equivalent components. The signal has good strength thanks to the use of a power transistor. The Q1 transistor is a unijunction of the time.
This 10, 25, 45 second and 5 minute timer has its times selected by the switches. The circuit...
This sensor circuit for currents of the order of nanoamperes was found in an American...
This HeNe laser power supply was found in the March 1989 issue of Radio Electronics magazine. This...