Thankyou Zooker. It seems to have enjoyed a healthy service life, albeit not operational in the same numbers as the 264. The other radar at Birmingham back then was a Plessey ACR430 which itself is likely to have been preceded by a Decca 424. Leeds Bradford had a 424 then a 430 but never any 50cm radars. I believe it was quite common for UK airfields to have both a 10cm and 50cm radar concurrently. Jersey and Bristol spring to mind.