The KT45 is rated as an audio output device with over 7 Watts output from a single stage. But the peak anode voltage is rated at 8,000 Volts. This clearly marks it out for duty as a line output stage in television type applications and indeed this was its intended use. The maximum anode dissipation is 21.5 Watts.
The KT45 appears to be a re-issue of the pre-war KT44 and has identical ratings but a different construction.
The anode side view. The supports are on extended plates located at the centre of the heat producing region.
The remains of the Marconi paper label.
The high voltage expected is catered for by having ceramic supports. The control grid has significant heat radiating fine present at the top.
Close-up view of the internal structure. The control and screen grids pass flat across the cathode tube. The beam plates can be seen within thew anode. The control grid has copper supports.
The classic envelope is 51 mm in diameter and, excluding the B7 base pins, is 121 mm tall.
References: 1043. Type KT45 was first introduced in 1947.