Hello.

Your listing for the 15A6 valve indicates an octal base.

The attached picture shows a Mullard 15A6 valve with a 9 pin base.

The picture is from my private collection and may be used on the page if desired.

Kind regards

Russell van Hooff.

Pièces jointes

• picture of 15A6 valve (187 KB)

Hello Russell,

Thanks for pointing out this potential error, very much appreciated.

In the upper area of this data page for the 15A6 you can see that the text is formatted in maroon color:

15А6

This means you are looking at a Russian / USSR tube - another indicator here is the "Common type USSR (SU)" maker entry for this tube, as is the transliteration to 15a6 (with a small a).

The correct listing has

15A6

on the top in regular color. That tube/valve is, as you indicated, fitted with a noval base.

That leaves the question if the data for the Russian 15a6 is correct, of course. The link on the bottom of its page leads to one model recorded for 1941 which uses the 15a6-s, a "long life" specs version of the tube. Since the remaining tubes are also octal and noval was a development that came to pass in the late 1940s/early 1950s only, it's very unlikely that this tube has a noval base.

Kind regards
Mark