The UU5 ia another classic Mazda indirectly-heated HT rectifier with a characteristic envelope shape. One side of the heater is connected to the cathode. The anode cavities are each made from two black pressed plates. This rectifier is designed to work into a maximum reservoir capacitor of 8 µF.

The UU4 (350V) and UU5 (500V) were used in larger radios from the mid-1930s and remained in the lists until the 1960s. They were staunch workhorses. Used in large numbers by the British services, there are plenty of good ones still around.

The classic envelope is of classic shape and 43 mm in diameter. The length excluding the B4 base pins, is 100 mm.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions

Rectifier	Vh	Ah	Va	mAa
	4.0	2.3	500	120

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 12 June 2007 {find valves by name}