The Radar that's gone missing from the grounds of what was the then CAA's TEE (Technical Engineering Establishment) was the TSF (Training & Support Facility) for the HSA 23cm radars.
The last of these 23cm Radars is at Heathrow and because of all the cranes being used there at the moment it's not used operationally too much.
The new radar at Bovingdon will replace H23 completely and is due to come into service soon, as is the new 10cm Radar at Gatwick as soon as all the teething troubles are sorted.