This is a well made tube tester. Made in Glendale, New York, USA.

It uses a 5U4 rectifier. I deoxidized and cleaned all the switches and tube sockets. I tested the 5U4 and replaced the only capacitor.

This machine can test old and new tubes.

It has a large tube roll chart built in.

 It has an extra gadget (Model G-140). It can test Nuvistor, Novar and Compactron tubes.

 The machine can test batteries, however I tried this function and I really don't understand how it works but in battery position the indicator dial moves.

Please look at the great box it comes in especially the dovetailed corners.

I tested several different tubes. The results are reliable and accurate.

SN 15817