[Granitehill]

If I remember right, it was also known as the Pye CAT. There was also a near equivalent from Murphy known as the CAS. The CAS and CAT radios were naval HF/MF equipment for small ships and as emergency reserves for bigger ones. They came with matching MF and HF transmitters, and were usually mounted as a stack of three items, plus a separate power unit which also contained a vacuum relay (!) for high speed TX/RX switching. TX output was about 40W.

Much more info in Electronic Engineering magazine June 1954 page 272. This article was written by one J.R. Humphries of Pye.