The Story of an Old Timer: Navigation by Radio Signal

Top right, a model of using radio signals for "fog" navigation for ships at sea developed by the Radio Section built all along the seashore mostly at existing lighthouses which led to landing beacons and direction findings for aviation.

Second image, a concept for a fixed runway landing aid (1926 by Dunmore). Two loop antennas - one modulated at 500 Hz and one at 1,000 Hz to give a landing corridor. This was built just northeast of the Radio Building.

Later that year (1926), Dr. Dunmore constructed a "movable" beacon to align with different runways with two different radio frequencies.

Third image, note that the coil antenna have been replaced with higher power single wire triangular antennas in two vertical planes and they can be rotated (on wheels)!