The V1505 is a power triode for audio or RF amplifier use up to 1.5 MHz. These valves would have been found in medium power transmitters for long wave and medium wave service. A pair operating in push pull can generate 800 Watts of audio to modulate an AM power valve.
This exhibit is of all glass construction whereas our other exhibit is mounded in a metal base shell and this adds to the height and thus lead inductance.
The graphite anode and ribbons connecting the pins to the electrodes. The electrodes are welded to a square of four posts secured in the sintered glass foot.
The graphite anode, grid winding, filament supports and within the grid can just be seen the top of one filament loop.
The ceramic spacer showing the metal rings either side that hold the spacer in place on the support rods. At the right side of the image can be seen the join between the electrodes and the rods fixed into the base.
The sintered glass base and ribbon connections. The annular pieces are probably a form of getter.
The filament tension springs and within the anode can be seen the hooked end and a loop of the oxide coated filament.
The wide glass tube envelope is 90 mm in diameter, and excluding the base pins is 240 mm tall.
Reference: Data-sheet. Type V1505 was first introduced in 1961. See also1961 adverts.