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.
We found this circuit in an 80's manual. The same configuration can be adapted to make use of...
This Mullard circuit was found in a 1969 documentation. It uses complementary transistors on the output and...
This is the traditional version of a neon flasher, found in a 2004 documentation. The capacitor...