The DD/207 is a double diode with common filament. It has a very low filament power and can only be designed for signal applications. The DD/207 was introduced by Mazda in 1937 and the metalised paint screening is typical of the period.

The classic envelope is 38 mm in diameter, and excluding the B4 base pins is 82 mm tall.

 
Pin Connections

B4	1	2	3	4
	a(2)	a(1)	f	f

 
Absolute Maximum Operating Conditions

Diode	Vh	Ah
	2.0	0.075

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 12 February 2008 {find valves by name}