The 5B4G is an unusual valve in that the envelope holds two triode valves that are hard wired in parallel. This was the American answer to the PX4 and the parallel construction enabled the AC anode resistance to be the low figure of 800 Ohms. The device is rated at 3.2 Watts.

The 6B4 is a type 6A3 on an octal base.

The filament is coated ribbon formed into an inverted 'w' in both anode cavities. The grid is a wire zig zag held on notched rods. The anode is formed of two pressed plates fixed together each with two half cavities. The anode cavities are 20 mm x 4 mm x 30 mm high.

The classic envelope is 48 mm in diameter and, excluding the IO base pins, is 111 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	-	f+	a	-	g	-	f-	-

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm	Pout
	6.3	1.0	250	-45	60	800	5.25	3.2W D_5%

Thanks to Frank Philipse for supplying the above datasheet

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