The UY85 is a half wave rectifier and would be used on small universal (AC/DC) mains appliances. The heater chain would draw 100 mA and this was to enable the small number of valves used in a broadcast radio receiver to be run without a large dropper (ballast) resister.

The UY85 can work into a maximum reservoir capacitance of 100 µF, as protection a series resistance of 100 Ohms minimum is required.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 57 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	-	-	k	h	h	-	-	-	a

 
Absolute Maximum Operating Conditions

Rectifier	Vh	Ah	Va	mAa
	38	0.1	250	110

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 07 June 2009