Radio Valves

Cossor P1 Bright Emitter Triode

imageP1 box P1 on bakelite base
open box
P1 anode
P1 base

This Cossor bright emitter triode is a P1. The valve is not gettered and probably dates from before the introduction of the stamp regulations on Nov 1st., 1922. The unusual cup anode is believed to be a way of avoiding a Marconi patent on cylindrical anodes.

The box is sturdily constructed from cardboard and the valve is protected by horsehair wadding above and below.

The base is typical of early 1920's valves, having split rather than spring pins and the electrode connection made by soldering to the outside of the pins just below the base.

Later examples were on this rather pretty orange red bakelite base, still using the same wiring method.

Below is a picture of a P1 from the 1935-6 A.C. Cossor Valve Manual, when the P1 was already a piece of history and considered important enough to the company to warrant a picture and a brief description. More history of the Cossor company.


© Andy Cowley, 2005-2012     Home

This page last modified by AJC on Friday, 26-Mar-2010