1259M

Early copies made at Bell of the British GEC E1189 S/N 12 magnetron brought to America by the Tizard Mission. The GEC sample was successfully operated at Bell on 6 October 1940. British asked Western Electric to run production lots of the tube for them.  Bell Telephone built very early qualification samples which were delivered within November 1940. A sample with dual marking Bell / WE, carrying the Bell developmental code 1259 M, is today on display in the online collection of the Birmingham University, record 144, ID number BIRRC-P090.

A total of some 60 additional prototypes were later made by Western Electric at the new magnetron facility in Chicago, Ill. with developmental code D-160052. Most of them were distributed to the MIT Radiation Lab and to American firms involved in the microwave radar developments. Other qualification samples were commissioned by British to Raytheon, but their quantity is unknown.

As the original British sample, both the Bell 1259M and the D-160052 units came with eight-fin radiator. We will see that their production outcomes from Bell related companies, REL3D and NTA98, were updated to the latest NT98 design, with four radiating fins.

The development of the E1189 magnetron at GEC can be read at this link.