The VR55 is a double diode triode RAF pre-WW2 receiving valve. The most likely use was at the end of the IF chain where the diodes would demodulate the AM signal and rectify an AGC control voltage, and the triode would act as the first audio amplification stage.

The external screening metalisation precludes an inspection of the actual construction of the valve.

The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 82 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8	tc
	m	h	a	ad(2)	ad(1)	-	h	k	g

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.2	250	-5.5	5	15k	2

This exhibit was last updated on 03 August 2006