Radio direction finder principle of Doppler radio positioning falconry tracker | Электронные компоненты и

Radio direction finder principle of Doppler radio positioning falconry tracker | Электронные компоненты и

DPL-400A brief introduction to Doppler radio direction finding machine

One Performance indicators

1.Measurement principle: Doppler effect (phase difference measurement, independent of the power size of a measured source)

2.Measuring frequency range:300-800MHz(other frequency measurement ranges can be defined by the author)

ThreeMeasurable mode: any pattern (as long as the receiver can receive the location)

FourMeasurement accuracy: horizontal direction:10Degree or so

Vertical direction:20Degree or so

5.The antenna of a direction finding machine is divided into about two dipole antennas (two upper and lower antennas make up an dipole antenna)

When the left and right two antennas are vertically polarized, the horizontal polarization is horizontally polarized, which can be properly adjusted according to the polarization of the measured source.

SixWith5V/1200mAHPower supply (can be charged by smart phone charger)

SevenPower supply: DC5v(USBInterface power supply

EightPower consumption: less than50mA

NineBuilt-in1KHzAudio modulation signal used to determine the orientation

TenOutput interface:SMA(headSMA-J)

11.SMAThe head can only be connected to the receiver, and it is not allowed to launch. Once it launches, it will cause permanent damage to the direction finding machine. Because of the burn out, it is not in the warranty list. Remember!!!

12.There is no receiver in the quotation

Thirteen This is the real Doppler radio direction finding machine principle, not the kind of Yagi antenna+Attenuator. Applications: find the interference sources of relay stations, radio direction finding competitions in schools, cheat in exams, search for launch sources, wireless wiretap, candid search for transmitters, search for missing friends and so on.

Two. Methods of use

Judgment method: when the distance between the two dipole antennas is equal to the source of the emission source, the internal1KHzThe modulated signal disappeared. That is, when the distance between the left and right two antennas is more and more equal to the measured source, the additional1KHzThe volume of the modulated signal is getting smaller and smaller until it disappears, and the source is on the symmetrical central axis of the two antennas. It is not difficult to see that the source of the measured emission is in a straight line and in which direction of the line can not be judged. Therefore, we need to change a place to measure the straight line again. The intersection point between the two lines is the location of the emitted source. Then we can drive to the nearby place for precise search. Try to find an open space when measuring, avoid misjudgement due to the refraction of walls and other obstacles, try to make the direction finding machine antenna away from the human body and avoid human error. When used, two antennas can be placed vertically or horizontally. When receiving the strong signal, the polarization mode of the transmitted source is the same as that of the antenna of the direction finding machine.