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 exhibit 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. See also 1925 adverts.

Pin Connections

B4

1

2

3

4

a

g1

f

f