This is a very nice newer model Precision 10-12 tube tester. The serial number has a “D” prefix character, and you can see the difference in the knobs used on the deck. The electronics appear to be the same as the older style 10-12s.
The Precision 10-12 is a good tube tester for the repair and restoration of vintage radios and amplifiers. Precision tube testers were built very rugged and are built almost Military grade. After the war I think companies were used to making Military grade equipment and it took a while for them to change.
Contact me if you have a tube tester you want calibrated.
