Newbie In some contracts, the specs for the tube, accounted for this. The tube, then, had a special construction(such as stabilizing rods, extra mica etc) This is when the tube, was different, and it had a different designation usually. But it only takes to look at a tube, and see the same internal construction, to know that there are no differences.
Tube myths Joint Army Navy vs Non Joint Army Navy
Joint Army Navy tubes, commonly referred to as JAN tubes, were tubes produced for the military. Tubes meant for the military, had to meet certain specs, as outlined, in the contracts, each manufacturer, had with the military. Though some contracts, called for a specially produced tube(RCA 5692, for instance), the vast majority of them, called for the same specs, as the industries, who tubes were mainly produced for, had. Consumer use, of tubes for audio, was small in comparison. The reason most think JAN tubes, are "better" tubes, is based on the myth, that they are different tubes. If the specs on a tube, say 6922 for example, were the same, for the Navy, as they were for , say, Hewlett Packard, then both tubes, were ran off the same lines(at different times, as orders dictated), with the same tooling, and same personnel. They are essentially, the same tubes. Most factories, ran a certain number of tubes, and then labelled them, as the orders, dictated. So a tube labelled H/P, was the same as a tube labelled Beckman. So you tell me, "which tube is better?"