The B65 is an audio double triode with a 6.3 Volt heater. The B36 is the same valve except for the 12.6 volt heater.

We also have the Experimental valve E1606 which is possibly the prototype of the B65.

The Osram paper label.

The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins, is 71 mm tall.

References: Data-sheet, Data & ¹⁰⁴⁰. Type B65 was first introduced in 1948. See also 1948 adverts.

Pin Connections

IO

1

2

3

4

5

6

7

8

g1(2)

a(2)

k(2)

g1(1)

a(1)

k(1)

h

h