Hello All-
In my opinion there is no military number for a 12BA6. As we all know the 6BA6 is also a 5749 (military number) or a 6660 (land mobile number). I have seen plenty of "JAN 5749" but never a "JAN 6BA6" that I recall. But, I have seen plenty of "JAN 12BA6", so that is my reasoning that a military number does not exist for the 12BA6.
Thanks for BW,
Byron.