The VMP4G is a variable μ screened amplifier pentode for RF and IF amplification in superhet receivers.

The silvering on the glass prevents inspection. Originally the whole envelope was covered in a metal paint. This has broken off to reveal the etched identification applied to the glass itself.

The classic envelope is 45 mm in diameter and, excluding the B7 base pins, is 118 mm tall.

 
Pin Connections

B7	1	2	3	4	5	6	7	tc
	m	g1	g3	h	h	k	g2	a

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm
	4.0	1.0	250	100	-2.0	8.0	5.0	2.7

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 19 April 2008 {find valves by name}