Mistral Yacht Yachts, Sailboats and All Things Boating

Beacon Antenna

How does an automatic direction finder (ADF) work? How small can you do?

ADF has been used for decades as an aid to navigation in aircraft, receives signals from the non-directional beacons. I'm surprised are not on the use of these small robots navigation (eg Roomba). My question is: How does the ADF? (I know there is something called a loop antenna sense …) Also, is there a size limit which makes them unsuitable for small robots?

ADF detect an electric field and magnetic field are perpendicular in space and their amplitudes vary sinusoidally with time. The magnetic field induces a voltage in the coils of the circuit ADF. By measuring the phase difference between the coils of the ADF is able to determine the direction of the beacon. Place the labels in the house and the use of automatic document feeder sailing is expensive and inefficient as the GPS and proximity sensors are available and perform better.

HO-68 CW beacon with Funcube Dongle and Arrow antenna

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