High school students builds NSA-like radio receiver detector

Recently two french high school students (Léo Poughon and his friend Thomas Daniel) published their work with SDR’s for their school project. Their project was to try and repeat the work of “Operation RAFTER” which was a technique use by GCHQ/NSA/MI5 in the height of the cold war to find hidden soviet spy radio equipment. Essentially, all superhet radios (almost any consumer radio is of the superhet design) will emit unintentional emissions from its local oscillator. By tuning to these unintentional emissions using a cheap SDR dongle it is then possible to know what frequency a radio is listening to.