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 configuration can be found in other articles on this site. This was obtained in 1998...
In the figure we show how to polarize a phototransistor to obtain sensitivity. The circuit is from...
This compact power supply can be used on the workbench for up to 1 A load. The transformer has 1 A secondary...