BA6646

BA6646 is not the designation of these tubes.
They were manufactured or selected for the former "Luftwaffe" (German Air Force). BA stands for Betriebsabnahme" or "Accepted work for the Air Force". The number is the reference to an examiner in person. The examiner inspected usually a large number of different tubes.
More information about these examination stamps is given in this link. If we know more about this particular examination number you will find a forum article below.

We try to show here all different tubes with this paricular BA-number. Each picture legend should give information about the actual tube type plus all other markings on that particular tube. We would like to show only one picture for each tube designation if all other markings are the same (incl. Date).

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