Actually the FV439 set up was at the periphery. the Centre of the hub was the Corps Comcen (A and B), which then branched out back to the loggie chain, Corps assets, and Divisions.
The Division Comcen was at the middle of it's own little world, branching out to Div asets, back to Corps and the Brigades.
I was a radio-relay technician, and repaired the C50/R236 setup (amongst others in my lifetime!) - hence my contribution to the Sankey communication trailers post.
The generators were Onan 3.5 kVA, which was standard for trailer, Bedford and FV439 mounted radio-relay systems. The terminal equipment, apart from FV439, used 6 kVA generators - so I guess there wasn't enough juice for some people.