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 good timer using only transistors was obtained in a 2003 documentation. The circuit has 6...
This is the project found in a 1981 publication, but it is still viable. It is a simple AM...
The circuit shown in the figure is indicated for alternative sources of energy, such as those...