VMS4B @ The Valve Museum

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VMS4B

Sensibly equivalent^¶ to:

AC/SGVM AS4125 CV1165 MVS-Pen VP4

See also:

Marconi Advert, March 1935 - M-OV's Screened Grid Valves - Marconi AC Valves Advert

Extras ▼

Marconi The Communications & Electronics Museum Trust Other VMS4B exhibits

The type VMS4B typifies the swansong of the screen-grid receiving valve with anode top cap. It is an improved, vari-mu RF/IF tetrode intended for domestic superhet receivers but it represents the final milestone on the road which started (barely 10 years earlier) with the Type S625.

VMS4B features a straight tube above the base to facilitate through chassis mounting. This exhibit is later after it was found that such screening was not required. The envelope widens out immediately above the base.

The Marconi branding of this M-OV valve. Note the internal bright gettering under the external zinc screening paint.

The classic envelope is 44 mm in diameter and, excluding the B5 base pins, is 108 mm tall.

References: Data-sheet & ¹⁰⁰⁵ Type VMS4B was first introduced in 1933. See also 1933 adverts.

Pin Connections

B5	1	2	3	4	5	tc
	g2	g1	h	h	k	a

Absolute Maximum Operating Conditions^¶

Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm
	4.0	1.0	200	80	0	8.0	1.5	2.9

Thanks to Frank Philipse for supplying the above PDF datasheet.

Updated November 13, 2021.

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