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?"
fletchj

Showing 1 response by gs5556

I don't know why or where this "myth" originated, but there are instances where, at least from my experience, the military version of a tube far outclassed the civilian variant: the Sylvania 6SN7 JAN CHS VT-231 and the RCA JAN 2A3 grey plates.

From what I understand, JAN tubes are manufactured to a military specification - not necessarily for the military. One of the most important parameters these tubes must meet is resistance to failure in high vibration environments and manufacture to tighter tolerances. For an audio application, this could mean a less microphonic tube. Not only that, but the mil-spec also dictated how they're packaged, shipped and stored - which means that the tubes found today probably had a better chance of surviving long term storage. Are they all better? Can't really make that blanket statement - because many of the commercial RCA/Sylvania/Ken-Rad/Philco/National tubes already met Mil-specs. But some specific variants ARE a different tube.