Tube tester for a Predicta 21EAP4

[Eric H]

Originally Posted by kx250rider

I think there are a couple of wires swapped for the Predicta tubes, to prevent the filaments from coming on if somebody puts a 2.7 volt tube in a 6.3 volt TV, or from installing a 6.3 volt tube in a Predicta. If you don't have the right socket, you can check the schematics of the Predicta and any other TV with that size socket but standard filaments, and temporarily swap the wires.

Charles

There's a difference but it's not the heaters, I think they swapped G1 and K or similar. Using the wrong socket just results in the meter pegging.