Beat me to it ! The antenna is for the Lorenz Beam Approach system, similar in layout to those seen on RAF bombers. It was part of the early Ground Controlled Approach (GCA) system in use until the 1950's, when more sophisticated ILS systems were installed at major airports and airfields. Basically, it recieves signals indicating that the aircraft is right or left of track, approaching or departing. When a constant signal (audible and or visual) is maintained, the aircraft is on track for approach to the beacon and, ultimately, the runway threshold, on the correct bearing for a landing approach.
Nice work BTW!