The VR65A is a television HF amplifier pentode for operation at 45 MHz with external metalisation as shielding. The original design was from Mazda, and other manufacturers copied this successful design after it had become established.

This exhibit is in a tubular envelope, the other VR65A exhibit is in a classic envelope of the same design as the branded SP41 and SP61, thereby suggesting its origin.

By contrast with the short lived EF50, the SP41, SP61 and the VR65A were virtually indestructible.

The 4.0 V heater was common in the 1930s when mains sets first began to appear.

The wide glass tube envelope is 30 mm in diameter and, excluding the MO base pins, is 80 mm tall.

 
Pin Connections

MO	1	2	3	4	5	6	7	8	tc
	h	k	a	g2	g3	m	-	h	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	4.0	0.95	200	200	-1.5	10.9	2.7	0.7M	8.5

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 03 January 2008 {find valves by name}