Very early unstrapped 3GHz cavity magnetron, derived from the British E1189 prototype, brought to U.S. and Canada by the Tizard Mission in 1940. Eventually the sample No.12, the first one having 8 cavities, was left with the Canadian National Research Council. Bell was asked to build a qualification lot of 30 copies. First samples were delivered under the Bell developmental code 1259M. More samples were built by the owned company Western Electric under the developmental code D-160052.
In 1941 REL was asked to build over than 600 GL IIIC 10-cm radar trailers for England undel the 'Lend and Lease' Act The magnetron E1189 was specified for this set. Almost certainly this magnetron was used also in the early development of the naval set RX/C, in the second half of 1941.
Volume production of the magnetron was run by Northern Electric, the Canadian sister comany of WE. The Northern Electric copies of E1189 magnetron were delivered under the code REL 3D. Some samples, one of them owned by the late Rod Burman, came with dual marking 3D / E1189. Several thousand units were almost certainly made for the GL IIIC and for other ground and naval sets. Unfortunately most of them were scrapped after the war to recover the gold used in the sealing process and the copper.
See 'THE INVENTION OF THE CAVITY MAGNETRON AND ITS INTRODUCTION INTO CANADA AND THE U.S.A.', PHYSICS IN CANADA November / December 2001.
The development of the E1189 magnetron at GEC can be read at this link.
|