The DMR(Digital Mobile Radio) can set single call, group call and all call directly through contacts. So what is the difference between them? 1. Single call Literally we can understand that this is a one-to-one call. Each of us will register a DMR ID through the call sign, which is the same as our mobile phone number and is not repeated. If you want to call the other party, you can directly e...
Scan is a very common and useful feature for amateur radio operators. When they are not sure which frequencies have a signal, they can turn on the scan function. To give an easy-to-understand example, suppose we have built 10 channels, but we are not sure which channel has a signal. At this time, if we turn on the scan function, the walkie-talkie will wait on these 10 channels. If there is no sign...
In addition to mobile phones, hams may also want to take a beloved two way radio with them when they travel. So, if it is an outbound travel, can they carry and use the radio? The answer is clear. If there is no relevant permission from the destination country, it is not allowed to use radio equipment casually. For specific usage issues, please refer to the laws and regulations of each country. Fo...
Sometimes the walkie-talkie is used outdoors or when exercising, but what should I do if it shuts down halfway through the use due to insufficient power? Do the following to keep you prepared. 1. Check equipment in advance This one is the easiest to achieve, that is, we must remember to fully charge the walkie-talkie the night before going out. 2. Switch the appropriate transmit power It is enough...
In fact, the attenuation of rain on EMW(electromagnetic waves) below 10 GHz is relatively slight, but for EMW above 10 GHz, the impact of rain attenuation is very obvious. When EMW passes through the rainfall area, the rain not only absorbs the energy of the radio wave, but also scatters it. This absorption and scattering together form electromagnetic wave attenuation. Scattering can also ca...
As we all know, walkie-talkies can make the signal stronger by adding gain antenna. Today we continue to talk about the topic of gain antennas. First of all, we need to understand the function of the gain antenna. Do you know how satellites receive communication signals? Logically speaking, satellites are far away from the earth. The higher the frequency, the greater the loss. So why do satellite ...
With the development of the economy, the people's requirements for long range communication have increased, and DMR radios have gradually begun to be used in public fields such as taxi dispatching, security, property management services, construction sites, hotels and restaurants. So how many kilometers can the longest call distance of a DMR radio reach? In an ideal situation (without any obstruct...
The critical value of 0.5W is defined because in the field of amateur radio communications, it is generally believed that equipment below 0.5W has low output power, limited use distance, and is unlikely to cause interference to other equipment or radio and television. Therefore, these low-power devices are generally considered not to require approval and authorization, such as some small radio tra...