As with the A tube, the B class I tube was also made in the spherical version which is shown here. Moorhead was quite good at marking the early contract valves with a B etched on the glass, a B or 1mon the pinch or class 1 in ink on the base cap. Moorhead Laboratories often times followed those markings with patent and Warning notices. Serial numbers Were also added quite consistently.![](../pics/aco0032a.jpg)
Taken from Joe's article.Thanks to Joe Gruber for sending the images.The balloon envelope is mm in diameter and, excluding the UV base pins, is mm tall.Reference: Joe Gruber. Type VT-B was first introduced in 1917. See also 1917 adverts. |
Pin Connections
| 1 | 2 | 3 | 4 | ![](../static/key.gif) g1 | f | f | a |
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Updated February 08, 2021.
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