Sensibly equivalent¶ to:
The VT62 transmitting valve, has a directly heated thoriated tungsten filament and has the electrodes sealed into a glass pinch.
The anode is of carbon and can dissipate 50 Watts. The high operating voltage leads to the positioning of the anode connection at a top cap. The grid is also moved to a top cap connection in order to allow the valve to operate at high frequency.
The valve is a 1930s design. Probably based on the M-OV type DET12 of 1936/7 and the original types had the carbon block anode. It is also possible that the earlier RCA type 834, with the UX4 base, was the design influence. and this exhibit was marked for Air Force use (VT prefix), the Navy also had a version of the valve and when the Common Valve designations appeared the valve was still in use.
The balloon envelope is 67 mm in diameter and, excluding the B4 base pins, is 138 mm tall.
References: Data-sheet & 1040.
Absolute Maximum Operating Conditions¶
Updated January 08, 2013. shape:balloon construction:pinch type:triode age:1930.1940 base:b4 pins:4 pin:1.- pin:2.- pin:3.f pin:4.f pin:tc.g1 pin:tc.a