We have no operating details for this transmitting pentode as yet. We know that ATP denotes an Army Transmitting Pentode and that it dates from the late 1930s. It was still in operational use in the early 1940s as it was given a CV designation under the common valve initiative.

Internally the three wire grids can be seen within the oval sheet metal anode. The valve is directly heated, possibly thoriated tungsten, the wire passes through the electrodes four times.

The type designation is printed on a band of external metalisation.

The classic envelope is 44 mm in diameter and, excluding the B7 base pins, is 124 mm tall.

This exhibit was last updated on 02 July 2002