Tetrode 6P3S (6П3С) produced in the small town of Fryazino is recently really scarce. It is russian equivalent of the 6L6, 6L6G, 6L6GA tubes. Offered piece was made in year 1952 (please see the gallery). Maximum anode voltage is 400V, second grid voltage 300V. Development and the first production of the 6P3S tube is bound to this small town, which is situated nearby the Moscow. Tube is new old stock and tested.