LMS10 versus CV64

The German, so-called Chinese, copy of the famous British CV64 cavity magnetron

Referring to the British postwar TRE report

Transcript of:
T.R.E (TRE) report T. 1858



My comments are:

This report shows that Telefunken must have faced considerable difficulties during the production of the LMS10, which is a (Chinese)copy of the British CV64 cavity magnetron.

TRE proved, that their machining had considerable mechanical shortcomings. This might well have been owed to the wartime circumstances, as these tested samples had been produced in late 1944 or in early 1945.

The use of an additional gettering facility, may indicate that Telefunken encountered sealing difficulties. Our own LMS10 (serial number 0587), like all other known samples, has a broken glass envelope due to its (brittle) glass quality.

Three of the tested samples showed, nevertheless, very good parameters and behaved like CV64.

During the Autumn DEHS meeting of 2005 in England, one of the attendees mentioned: that the Germans used linear strapping, maybe due to the lack of understanding of its principle. In my opinion this does not fit with the facts shown in this TRE report.
Bearing in mind, both photographs of LMS10 and CV64 and given the perfect parameters of three out of eight LMS10 samples tested, we have to conclude that his statement does not match with reality. What might have happened is, that the strapping of CV64 had been individually phase adjusted, whereas the Germans (Telefunken) employed not adjusted strapping(pre-fab.). The lack of efficiency of several LMS10 samples, may be owing to incorrect production-techniques (procedures) and wartime circumstances.
Considering the two photograph, the only instant observation to be made is, that it seems that the Telefunken LMS10 magnetron-strapping turned(rotated) in an inverse direction.

Brian Callick mentioned: that the Germans used in contrast a pure copper anode block, which is quite difficult to machine. Bearing in mind the shortage of qualified labour and the structural destruction of Germanies industry (late 1944), there had been, probably, no alternative to increase production quality.

Arthur O. Bauer

Consider also the famous MIT paper on: Strapping technology

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