No.53
A very cool direction finding setup. by Byon Garrabrant, N6BG.
http://byonics.com/tdoa/ No.54
No.55
No.56
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No.58
No.59
The simple explanation is the circuit switches between the two antennas at an audio frequency. The result at the coax is a phase modulated signal, the phase shift depending on the distance between the antennas and the angle of arrival. The phase modulated signal is fed to an FM receiver, which produces a tone at the switching frequency.
Maximum audio level is produced when the two antennas are in line with the direction to the transmitter (maximum phase difference). Minimum (or zero) audio level is produced when the line of the two antennas is perpendicular to the direction to the transmitter (minimum phase difference). Minimum signal level is typically used to determine direction because the null is so much sharper.
-Joesugar
No.62
>>53>>54I built this today. It works well. Accurate to 10 degrees.
No.64
>>62Substituted the pic for a 555 timer.