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How to amplify the radio signal? How to use the gain antenna effectively?

Date:Mar 10, 2020

If two radios have the same gain antenna, then its transmission efficiency and reception efficiency will increase. How does the gain antenna work?


walkie-talkie-free-space


How does the satellite receive communication signals? Theoretically, the farther the satellite is from the earth, the higher the frequency. Due to the ionosphere and the long distance, the loss will increase. Why can satellite communication signals use a communication frequency above 5GHz? It is because the gain antenna can make up for the loss of free space and can achieve lossless signal reception. Similarly, installing a gain antenna on the radio can reduce the loss of free space, thereby increasing the communication distance.

There are three ways to solve the interference, one is to add a repeater, the other is to increase the antenna gain, and the third is to increase the output power of the radio.

If the power of the transmitting device is high and the power of the receiving device is low, then adding a gain antenna to the receiving device will enhance the receiving and transmitting of the receiving device. Therefore, the greater the power of the radio, the better, and the larger the antenna gain. If a repeater is added, the communication effect and speech intelligibility will be very good in a certain area.

Which antenna is suit for your radio?



Generally, the length of a longer antenna is higher than that of a short antenna of the same technology. The antenna of a handheld walkie-talkie must also consider portability in addition to the gain. For some dual-band and multi-band walkie-talkies, the antenna design must take into account each frequency band. , So you can only reduce the gain.

gain-antenna
For users who prioritize portability, a short antenna can be selected. Although the gain is not good, the radio portability is improved. For users who prioritize transmission performance, they can choose a long antenna. Although it will affect the portability of the walkie-talkie, it can send and receive radios.In addition, when selecting the antenna of the paired radio, in addition to paying attention to the shape, length, and gain of the antenna, you must also pay attention to whether the interface of the antenna matches the interface of the radio.



How to play the effect of the antenna?


The basic transmission of the VHF / UHF frequency band commonly used by walkie-talkies is mainly straight line transmission, and the blockage of buildings has a greater influence on its transmission. So the height advantage of the antenna is very obvious. The ideal environment for using the two-way radio is an open area. If you are in a low-lying area or surrounded by high-rise buildings, it is difficult to give full play to the power of the antenna.

outdoor- antenna
Sometimes moving the antenna horizontally for a distance will cause a significant change in the signal, which is more obvious in the UHF band with shorter wavelength. Some users will use the car antenna as an outdoor antenna, and the effect will be better than the intercom calling in the room. If you mainly focus on the communication of a certain local repeater station, you can observe the change of the received signal strength and then pan the position of the outdoor antenna to find the position where the received signal is the largest. Usually this is the transmitting position with the best relay effect.

Based on the same reason, when the communication signal is not good, walking to a relatively open place and moving the position signal back and forth and left and right may improve.