This can be considered a complete laboratory for the repair professional. A full featured signal tracer with 13 tubes. The circuit is from the March 1946 issue of Radio Craft.
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...
This stage for JFETs was found in a 1965 US publication, but is valid for modern components. |...
I found this simple circuit from an English magazine from 1984. The circuit can be easily...