7308 tube code question

In the case of the delta being in paint on the tube, that doesnt' signify holland manufacture. the * does mean US made, sorry I didnt' notice that in the orig. post. Tube codes such as * and delta are always etched on the amperex, near the bottom of the tube.

-Ed

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.

The VR is the Philips/Mullard/Valvo code for a E188CC or a 7308 tube. The 5 after the VR denotes the fifth variation of that tube. The "*" is for Hicksville, NY, whereas the delta A would be Heerlen, Holland. The '5' after that would probably be 1965, as this tube wasn't made in the 50s and I don't think Hicksville was making them in '75, but this is a close one. If it has white labeling and given the fact that it's a CEP marked tube, I'm 95% sure it's 1965. And finally, the B is for February.

So we have US made Amperex 7308s, which are fifth versions and are consistent with a Feb. '65 manufacture date.

Simple, no?

Now whether the tubes test strong, are well matched across the triodes and are not mircophonic, I can't say. Plug 'em in and see.

Take care, Chris