Classic British Flight Sim

Re Ben's original question, the only navaids at OD were:
PAR on 18 and 36
Primary surveillance radar (Plessey AR15 from memory)
UHF and VHF D/F

I left in 1991 and I believe that a SSR feed was introduced some time later, but whether it was a SSR radar head at OD or a remote feed I'm not sure.