The VR54 is a signal double diode. Our exhibit is also marked 1638 but we cannot find data on the 1638 and the number does not fit the American naming convention. The VR54 is equivalent to the commercial EB34.

The glass envelope has been screened with an external copper metalisation that has then be painted black.

The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins, is 63 mm tall.

References: Datasheet, ⁴⁰⁰¹, ⁴⁰³⁹, ¹⁰⁴⁰, & ¹⁰⁴³. Type VR54 was first introduced^¶ in 1941.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions^¶

Diode	Vh	Ah	Va	mAa
	6.3	0.2	200	0.8

Thanks to Frank Philipse for supplying the above PDF datasheet

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