The 6A6 is a 6N7 on a UX7 base (actually the small seven pin or USS7) and dates to the early 1930s. The Tung-Sol data-sheet refers to the 6A6 as being on the medium seven pin base which is the UX7.
It was designed for use as a zero bias Class B push-pull audio output stage. The design was a development of the American Type 53 and the later and more popular versions were the 6N7, 6N7G and 6N7GT.
The test data is on the label.
The twin sections with copper control grid supports and radiating fins at the top.
Here the two sections are clearly seen as separate.
Side view.
The classic envelope is 44 mm in diameter, and excluding the UX7 base pins is 100 mm tall.
References: Data-sheet & 1043. Type 6A6 was first introduced in 1933. See also1933 adverts.
