This exhibit is labelled as a barium tube, clearly indicating an oxide cathode. The envelope also gives the heater voltage as 2.0 V and the anode voltage as 200 V. This valve is given as originally manufactured in 1929. The electrodes are pointed at an angle to the horizontal and the filament is a single 'V'.

The balloon envelope is 44 mm in diameter and, excluding the B4 base pins, is 86 mm tall.

Reference: ¹⁰⁴³. Type H210 was first introduced^¶ in 1929.

 
Pin Connections

B4	1	2	3	4
	a	g1	f	f

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	2.0	0.1	150	-1.5	1.0	50,000	0.7

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