Tracking Cold War Signals

The Cold War was also a war of signals. This battle comprised chatter over radio, Morse, data and technical signals. Eavesdropping on enemy communications and analysing their technical signals was a vital part of that battle. However, to know where those signals came from was just as important.

Directional antennas find the bearing of a signal. Early simple loop antennas had to be turned mechanically to find the signal bearing. With two or more such antennas on different locations, the target is located at the crossing of those bearings, but it was a cumbersome task. Later, double loop antennas and Adcock antenna arrays with four elements improved performance, but many more special direction finding (DF) antennas were built to locate signals, and some were quite extraordinary.