The VT107 (N43) is an output pentode suitable for both audio and video use. The load impedance required is 5,400Ω. The cathode resistance is 90Ω and in single ended configuration the output is 4.5 Watts.
Outside the box anode top and bottom are screens connected to the suppressor grid. The copper supports of the control grid have heat radiating fins fitted.
The box anode end on. The horizontal wires at the top connect the cathode to the suppressor grid and the two vertical support rods.
The anode front view.
The connecting wire between the suppressor grid and the cathode. The not at the top of the g3 support indicates a true pentode rather than a beam tetrode construction.
The classic envelope is 56 mm in diameter, and excluding the B7 base pins is 134 mm tall.
References: Data-sheet & 1040. Type VT107 was first introduced in 1936. See also1936 adverts.
