7308 tube code question


I just received 10 NOS Amperex 7308 from my father. Each tube has the following markings:

All lettering in white
USN-CEP
A white triangle like symbol
VR5 *5B etched in the glass

The only nomenclature that I am familiar with is the USN = US Navy. What does the rest mean? What do people think of these tubes in a phono section of a pre-amp designed to take 6DJ8's
brf

Showing 1 response by fletchj

All JAN tubes, were made in the USA. That was a big reason Phillips moved a factory, to America. The USN-CEP, indicates that is was JAN, made specifically for the US Navy specification. The etched codes, indicates origin, construction, model, and authorization(acceptance)no.
They should be extremely suitable for phono sections, as this was a selected 6922, based on noise, section matching, failure rate, and on spec. longevity, to name a few.