Sensibly equivalent¶ to:
The PX4 is one of the classic audio power triode valves and this one is branded Marconi. The design belongs to M-OV and so Marconi and Osram are used to brand the valves.
This exhibit lacks the treated anode of later versions and features a bright nickel anode.
The filament is a single wire formed vertically within the anode cavity into four inverted V's. The grid is a single wire formed between two vertical notched rods 1.5 mm in diameter. The grid zig-zags around the filament.
The electrode system is only about 5 mm from front to back, but is 35 mm wide (including support rods) and 45 mm high. The classic envelope has a maximum diameter of 58 mm and excluding the B4 base pins, is 120 mm long. See also PX4 and PX4.
References: Datasheet, 1005, 1040 & 1043. Type PX4 was first introduced in 1929.
Absolute Maximum Operating Conditions¶
Updated April 05, 2015.