I think I've posted this before, but for anyone who cares,
here's the manual that came with a Plessy ACR 430 in the 1970s - hope I'm to infringing the copyright too much!
The 430 was a development of the 424 - essentially it was a 424 with the addition of the high beam. Both, I believe, were originally designed for use on ships. Despite some peoples' reservations, I always thought it was a fun bit of kit although you had to keep it (both channels) tuned to get the best performance, and sometimes to tilt the antenna during an SRA to keep the aircraft in the pencil beam so that you got a solid blip. Hard to imagine a controller being allowed to do that sort of thing these days but it sorted the men from the boys and the women from the girls (sorry if I'm not allowed to say that any more)! Did many 1/2 milers in my time, mostly in anger (which meant there wasn't any need to do practices in nice weather).