The VU71 is a pre-CV UK services designation rectifier. The commercial type closest in specification is the U52 full wave rectifier.

The filament is an oxide coated ribbon. Between the anodes in the centre of the envelope are two vertical support rods. These connect to the top of the inverted V loops and provide support and tension via curved springs above the mica.

The classic envelope is 51 mm in diameter, and excluding the IO base pins is 118 mm tall.

Reference: Datasheet. Type VU71 was first introduced^¶ in 1938.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	-	f	-	a(2)	-	a(1)	-	f

 
Absolute Maximum Operating Conditions^¶

Rectifier	Vh	Ah	Va	mAa
	5.0	3.0	500	250

Thanks to Frank Philipse for supplying the above PDF datasheet