NR57 @ The Valve Museum

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NR57

Sensibly equivalent^¶ to:

AC/P CV1179 ML4 TT4

Extras ▼

Unknown HMS Collingwood Museum Other NR57 exhibits

The NR57 is an audio output valve, in fact a type ML4 from M-OV made for military use in WWII. With a 4.0 Volt heater it was designed to be mains driven, so it is surprising to find the output power is so low. However, the data-sheet says that it was for use as a driver for a larger output valve.

The classic envelope is 42 mm in diameter and, excluding the B5 base pins, is 98 mm tall.

References: Data-sheet & ¹⁰⁴³. Type NR57 was first introduced in 1929. See also 1929 adverts.

Pin Connections

B5	1	2	3	4	5
	a	g1	h	h	k

Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm	Pout
	4.0	1.0	200	-13.5	17	3,700	2.7	0.65W

Thanks to Frank Philipse for supplying the above PDF datasheet.

Updated December03, 2012.

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