European six-pin binode base (B6)

European B6 has six pins on a 24 mm circle, with uneven angular spacing. The drawing distinguishes intervals of 40 and 60 degrees, producing a layout recognisably different from other six-contact bases.

The male pins are 3.2 mm in diameter and 17 mm long. The historical term binode does not replace the mechanical description or, by itself, define the valve's electrical characteristics.

This construction is not treated as American UX6 or Eu U. The full designation and drawing dimensions must accompany the six-pin count.

The layout is clearer when the empty sector is included: three intervals of 40 degrees, two of 60 degrees and a 120-degree opening complete the circle. Six pins alone might wrongly suggest regular 60-degree spacing. The gap is instead a tangible identification feature.

Both drawings agree on the reference dimensions: 24 mm pin circle, 3.2 mm pins and 17 mm length. They provide no tolerances here, so none are added. Male-base dimensions do not automatically prescribe socket-hole diameter or spring force.

Numbering conventions differ: one includes a position marked 7, while another numbers the six contacts 1 to 6. Numbers must not be overlaid without checking orientation and the valve's pinout. STV280/40Z is an example of this base, not a universal assignment of functions to its six contacts.