This is a mystery valve. One can read the the word 'type' but not the rest. The base is a nickel shell with a central groove. This base was used only by M-OV for its early Valves.The internal construction is similar to the early 'R' Type valves with a horizontal cylindrical anode, single straight filament and wire helix grid.The filament fixing is a folded and crimped support.The balloon envelope is 40 mm in diameter, and excluding the B4 base pins is 79 mm tall.Reference: Observation. |
Updated January 05, 2013.
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