sentences:  ... Churchill, so far from pondering whether to save Coventry or safeguard Ultra, was under the impression that the raid was to be on London".Scientist Reginald Victor Jones, who led the British side in the Battle of the Beams, wrote that "Enigma signals to the X-beam stations were not broken in time" and that he was unaware that Coventry was the intended target.Furthermore, a technical mistake caused jamming countermeasures to be ineffective.