The VT60 is an 807 for the pre-war UK RAF. The 10E/1144 is the old RAF stores code.
The parameters given are for single ended use. When used in a class AB1 as a push pull pair with 600 volts on the anode an output power of 65 Watts was normal.
These valves were much used in medium power amateur radio transmitters for high level modulation. In this use the output transformer, called a modulation transformer, would be impedance matched to the anode circuit of the RF power valve. The audio power would increase or decrease the amplitude of the RF envelope.
The classic elliptical lower screen of the 807 seen above the pinch. The base is ceramic and thus less likely to absorb moisture - a prerequisite for airborne use.
The ribbed anode, lower mica disc and elliptical lower screen.
Here the two wire inner grids are visible as is the bright beam plate either side of the grids.
The ceramic UX5 base.
The classic envelope has a maximum diameter of 50 mm and a length, excluding the UX5 base pins, to the tip of the top cap of 126 mm.
