The 37 is a low impedance low gain amplifier triode. One of its original intended applications was as an 'anode bend' signal detector. The 'anode bend' detector gives a reasonable audio gain with appreciably less audio distortion than the better-known 'grid-leak' triode detector. Use of the Type 37 as a detector became obsolete when superhets with AVC and double-diode-triode became the norm. However, the Type 37 lived on for another decade in its general-purpose role.

It would have been found in domestic receivers used for detectors, oscillators, amplifiers and AGC.

It is listed in 1951 but is removed in later information manuals.

The classic envelope is 36 mm in diameter and, excluding the UX5 base pins, is 85 mm tall.

 
Pin Connections

UX5	1	2	3	4	5
	h	a	g1	k	h

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.3	250	-18	7.5	8,400	1.1

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 December 2007 {find valves by name}