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
| 1 | 2 | 3 | 4 | a | g1 | f | f |
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Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vg | ra | gm |
| 4.5 | 0.6 | 30-120 | -6 | 20k | 0.45 |
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Updated December26, 2011.
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