Amazing All-Band Receiver

Posted on Feb 5, 2014

The Amazing All-Band Receiver is basically a diode detector followed by a high-gain audio amplifier. This is not a multi-band receiver; it picks up everything at once! The detector uses a biased Schottky diode for excellent sensitivity and bandwidth; the detector will detect signals from below the AM broadcast band up to the microwave bands. The n

Amazing All-Band Receiver
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umber of interesting signals is surprising; it is fun to drive around listening to the numerous strange sounds. By trying different antennas and locations, this receiver has picked up AM radio stations, FM stations, TV video (buzz), car lock transmitters, cell phones, and even the microwave oven (a whoosh-whoosh sound as the microwave spreader rotated). It isn`t clear how FM stations are demodulated; perhaps the antenna Q is sufficient for slope detection. (See reader Karen`s excellent theory. ) Even the familiar buzz from a narrow-band FM pager transmitter has been heard - somehow. There are some mysterious signals out there, too! What is that occasional descending whistle over by the highway Some vehicles emit a curious buzz, too. If you hear a mysterious click-click now and then, its your cell phone! Don`t expect to tune in international shortwave stations. This receiver is for strong, local sources. The advanced experimenter will find it useful as a detector section for low power tuned receivers. Other signals that should be easy to receive include in-flight aircraft transmissions (this passive receiver will not interfere with communication/navigation systems), CB radio transmissions, amateur transmitters, "bugs", wireless networks and devices, radars, radio control transmitters, certain security/alarm systems, and even unexpected oscillations in your next circuit. A short, perhaps 6", antenna is a great general-purpose...

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