How to choose compatible antenna for two-way radio

The antenna is one of the most important parts of two-way radios, to improve transmission efficiency and making sure communication clear and exact, replacing the antenna is a cost-effective method. It is not easy in fact, if you choose the correct and compatible antenna, your two-way radio will achieve better transmitting and reception, but how to choose compatible antenna for two-way radio?

Four tips for choosing the compatible antenna:

1. The frequency of the two-way radio should overlap or coincide with the antenna frequency.

Generally, two-way radios and antennas will have a default central working frequency when they leave the factory, good performance can be achieved with this frequency. For example, the VHF antenna frequency range is 136-174MHz, usually, the center frequency will be 144-148MHz. The center frequency point is the best operating frequency point for the antenna. The antenna at this point has the highest efficiency, the largest gain, and the smallest standing wave. Therefore when choosing an antenna, the frequency should overlap with the two-way radios.

Recently our customers who bought Retevis RHD-771 antenna meet the problem that the antenna doesn't work on the VHF band, UHF band works. As a result, our technician tested it on Retevis RT5R, Ailunce HD1, and Retevis RT3S, the performance of RHD-771 is worse than the original antenna of the three radios.

The three model radios tested by the network analyzer, and the corresponding SWR at center frequency point 144/430MHz, all are high:

RT5R(20.9/2.0)

HD1(1.8/3.5)

RT3S(5.9/2.0)

The center frequency point of the RHD-771 antenna is 144/430MHz, the corresponding SWR is 1.4/1.2, it normal, pls check the below photo:

According to the pictures, we can get that the bandwidths in the VHF band of the 3 radios are very narrow, a slight deviation from the center frequency will cause a large increase in the standing wave. Their original antennas are specially tuned for this model of radios, their center frequency is completely consistent with walkie talkies', so the VHF band can reach the best performance.

The RHD-771 is a universal replacement antenna, if there is a slight deviation from the center frequency of the two-way radio's, the SWR will be high, coupled with the high sensitivity and poor penetration of the VHF band, resulting in a large reduction in the effectivity of the VHF band; the UHF band has wide bandwidth and strong penetration, and the impact of deviation is small, so customers will feel that UHF is better than VHF band. For example, the center frequency of RT5R in the VHF band is 155MHz, which is a large deviation from the RHD-771 antenna's 144MHz, so the performance of the original antenna is much better.

2. The working frequency of the two-way radio must be within the antenna frequency range;

For example, the frequency range of your two-way radio is 400-450MHz, then you can choose the single UHF or dual-band (UHF and VHF ) antenna, but the frequency should cover 400-450Mhz.

3. The antenna interface of the two-way radio should be compatible or complementary with the antenna connector;

There are many types of antenna interface. The portable radio antennas and mobile radio are different, if you are not sure which one is compatible with your two-way radio, you can reference our antenna connector chart or consult us, we are always ready to help you.　

4. The transmitter power of the two-way radio should be within the maximum power that the antenna can withstand;

Antennas have certain input power limitations. The power input from the radio station to the antenna should not exceed the maximum power of the antenna, which will not damage the equipment, but also improve the performance. When choosing an antenna, we must pay attention to that.

With the 4 tips in mind, you may know how to choose compatible antenna for two-way radio, if you can't find the suitable one, we also supply customization service, pls don't hesitate to contact us.

Email: info@retevis.com