AV25

This tube is a demonstration triode intended for educational use. The filament consists of four parallel oxide coated wires. These are located parallel to the plate. The widely spaced grid is placed between the filament and plate in the normal manner. The plate itself is coated with a phosphor which fluoresces green under electron bombardment. The higher the plate voltage (300v max), the greater the fluorescence. A unit was developed to use the tube and its companion AV43 Demonstration Cathode Ray Tube and these units were widely used in physics laboratories in schools and universities. See full "Radiotronics" October 1956 and January 1959 below.

This tube was designed by Vivian Anthony from AWV and details on the tube specifications were never published in ordinary tube data books.