The B319 from M-OV, badged as a Marconi valve, was designed for the introduction of Band III television. In the UK this service commenced in 1955.

The B319 was specifically designed for cascode operation as an RF amplifier up to 250 MHz. The cascode configuration was for triode one to be operated as a grounded cathode stage directly coupled to triode two. Triode two was connected as a grounded grid stage.

The Marconi paper label is visible but damaged.

See also PCC84.

The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins has a length of 45 mm.

References: Datasheet & ¹⁰⁴⁰ Type B319 was first introduced^¶ in 1954.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	k(2)	g1(2),s	a(2)	h	h	g1(1)	k1-in	k1-out	a(1)

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	7.4	0.3	90	-1.5	12	4000	6

Thanks to Frank Philipse for supplying the above PDF datasheet