Thomson CSF CV6124

This device weighs 22kg and has a very strong magnet. A plate on the side indicates the following parameters:

It measures 290x140mm overall and has a 5-pin plug. It appears to be water cooled. Output is via a coaxial connector.

The device is marked with UK Patent No. 699893 and US Patent No. 2880355. The device is a carcinotron, a form of backward wave oscillator.