System for detecting miniature eavesdropping transmitters emits synthetic noise signal or pseudo-noise signal as test tone, compares with demodulated output signal of search receiver

摘要

The system has a sound source (9) for emitting test tones into a room (1) under investigation, a search receiver (3) for receiving the miniature transmitter signal (HF) and an evaluation device for comparing the emitted test tones with the demodulated output signal of the search receiver. A synthetic noise signal or pseudo-noise signal is used as a test tone.