Home: Miscellaneous: 4 PIN VALVE WITH SIDE CONNECTION, 1920's
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4 PIN VALVE WITH SIDE CONNECTION, 1920's Unidentified valve with a 4-pin base and a further connection on the side. This connection would be for a further grid, making this a four-electrode valve; this extra grid is probably a space charge grid that was introduced by Irving Langmuir in 1913. The space charge grid is positively biased and spaced between the control grid and cathode. Alternately it could be a bi-grid type where the extra grid is used to control separately the anode current. The valve is marked 6V, (Heater voltage.!) A1774 |