The Optoelectronics, Inc. R506 RF Detector works in the range of 50MHz-6GHz and is useful for locating unknown transmitters in the nearfield. The R506 detects analog as well as digital transmissions and FM as well as AM signals.
The R506 has three ways of alerting you that it has detected a signal. There is a beeper, vibrator and acoustic alert. The acoustic alert broadcasts the noise through its speaker or though the earphone jack. There is also a 10 segment LED bargraph that displays the strength of the signal captured.
The R506 comes in a compact hard plastic case that fits in the palm of your hand. The built-in telescoping antenna ensures you'll never be without one.