The Cosmos A45 is a bright emitter receiving triode that was introduced by Metro-Vick Supplies, a subsidiary of the Metropolitan Vickers Electrical Co Ltd, in 1925. The first production had a metal base skirt and later types had the bakelite skirt as shown in the picture above. The M over V logo can also be seen as can the filament rating of 4.5 Volts at 0.6 Amps. Both versions employed the same 30 mm wide envelope.
The valve was a general purpose type with an amplification factor (μ) of nine. The control grid voltage range was between 0 and -6 Volts.
The has a closely spaced cylindrical anode and control grid. The filament is a straight tungsten wire that is kept under tension by a wire spring at the top.
See also A45 for our other exibit and close-up images.
The wide glass tube envelope is 30 mm in diameter, and excluding the B4 base pins, is 92 mm tall.
References: 1003 Type A45 was first introduced in 1925.
Absolute Maximum Operating Conditions¶
Updated December26, 2011. shape:wide.glass.tube construction:pinch type:triode age:1920.1930 base:b4 pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f