The WA Types (under PROGRESS OF DEVELOPMENT heading) of radar sets can be found Here

and also read the first paragraph and see the photograph of HMS Rodney with her 79 aerial Here

The Type 79, as modified, was the Navy's first radar set. It was reliable and gave excellent high cover but these advantages were outweighed by the following disadvantages:-

a. Poor low cover

b. Wide beam width making the set useless for use with a PPI

c. Wavelength of 7.5 metres (40 MHz) was not a band allocated for future naval use.

The 79 had its fitting programme suspended and ships got the 281 in lieu, but it was unreliable due to poor design and the fact that it had been altered and modified continuously during the war without any single end in view. The 960 replaced both the 79 and the 281, although it too had problems with the conventional PPI - its wavelength was reduced to 3.5 Meters {86 MHz approx}. For that reason they fitted it with a UDU "Universal Display Unit" in lieu of a PPI.