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...
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...
"I'm in junior high school now. I love radio. I also learned some amateur radio knowledge by myself. I often communicate with my friends using FRS walkie-talkies. Can I get a radio license?" A seemingly simple question, but also asked a lot of HAM. 1. Can children take the radio station operator's license test? In China,there is no age limit for participating in Class A and Class B operational tec...
Dual standby: Dual band radios generally display two lines up and down, which are generally called the main channel and the secondary channel. When there is no signal coming, the main channel and the secondary channel are in standby mode. When there is a signal coming in, the walkie-talkie will choose the signal that comes first. When there is already a signal coming in, another signal cannot come...
Walkie-talkies are commonly used in underground parking lots in residential areas, shopping malls, and hotels. However, communication signals can be weak due to the underground location, which affects communication. How can we enhance the signal when using a walkie-talkie in an underground parking lot? In general, the reinforced concrete walls in the basement of residential buildings are quite thi...