I spent several years flying the Searchwater radar during the development phase. We had a Viscount at Radar Research Squadron RAE Bedford
That point by tinribs is excellent and itself warrants a book! Start with "Could we do that today?". Searchwater's designation is ARI (Airborne Radio Installation) 5980 (and /variants). The "5980" tells you much. Primarily, sourced from an RRE or RSRE specification and MoD get (got?) commercial exploitation rates (mucho dosh) if sold to anyone else (like Spain). We no longer have RSRE. And QQ are shedding jobs by the hundred. You soon get to the heart of the so called Defence Technology and Industrial Strategies published by the last regime.