Sensibly equivalent¶ to:
The VT-135 is an RCA type 12J5GT supplied to the US Government. The only difference between the 12J5 and 6J5 is the heater.
The electrical characteristics of each half of the 6SN7 match those of the 6J5. Additionally the 6J5 was developed into a VHF oscillator/amplifier and the resulting valves are 7193 and DET20. Both these derivatives have grid and anode brought out into top caps and the designs are very similar but not identical.
The wide glass tube envelope is 27 mm in diameter and, excluding the IO base pins, is 60 mm tall.
References: Datasheet & 1040.
Absolute Maximum Operating Conditions¶
Updated September 12, 2013.