The YL1190 is a quick heating double beam tetrode VHF-UHF power valve. It provides over 30 Watts at 200 MHz and just under 20 Watts at 500 MHz.
This exhibit carries a Mullard experimental label and is also marked as a non working 'dud'.
Quick heating valves were used in man-pack transceivers and similar applications where battery power was limited.
One of the coated anodes.
The bright centre metal is the beam plate with the screen grid within. The two control grids are of frame construction.
The microscope reveals the filament construction to be a multitude of oxide coated wires held in a frame. In effect constructed as a frame grid but the filament wires are then oxide coated.
One of the frame grids with the filament wires above.
The wide glass tube envelope is 28 mm in diameter and, excluding the B9D base pins, is 71 mm tall.
