identifying a 12ax7

I went through my stash of 12ax7's and came up with some cool UOS 12ax7's that I am trying to identify. I will take a few pictures in next day or so and post them so maybe we can figure it out via getter and halo construction.

One tube I am curious about is one that is labeled National in red, but has made in Great Britain in white somewhat under the National label. Im asking because the only reference to National I have found is ones produced for National by Tung Sol in the 60's. The only tube manufacturer in GB I know of was Mullard. I know this tube is not a "fake" as I personally pulled it from my grandmothers Hammond Organ after she passed away. I also have some 12au7 Hammond relabels that were made in USA that work well in my buddies Bass 400+ in the driver position.

bjorn218 said:

The only tube manufacturer in GB I know of was Mullard.

Click to expand...

Brimar, Ediswan (Mazda), GEC/Genelex, and Tungsram all made vacuum tubes in Gt. Britain at one time...

Photos will help immensely.

National re-branded everything. Your "Great Britain" tube may actually have been made there. Or, even more likely, it was made in an Eastern Bloc country during the cold war, and painted with "Great Britain" to bypass import restrictions.

Photos will tell.

- Thom

Any REAL Blackburn factory British Mullard 12AX7/ECC83 will have:
-a single seam across the top of the tube
-a (usually) acid etched set of codes across the glass near the base of the tube with I61, I63 or I65 above a datecode that starts with the letter B for Blackburn

The datecodes are very rarely missing but it IS possible to run into a Blackburn Mule with missing codes. I've never seen one without the seam.
As was mentioned, there were several British tube manufacturers and I don't think all were BVA members. Brimar was a big one.
I've never seen British made Tungsrams. That doesn't mean it didn't happen. You need a PhD to know even just a LITTLE about tubes and their history.
Just rest assured that labels mean NOTHING.
It's as common to find American tubes with Mullard labels (I have some sexy Mullard 6V6s) as it is to find Mules that say Electrohome on them.