Compostable Mailing Bags,Poly Mailer Plastic Mailing Bag,Biodegradable Waterproof Mailing Bags,Courier Mailing Bag Dongguan Pasike Packaging Co., Ltd. , https://www.dgpasike.com
Big talker: outdoor walkie-talkie selection and use
Walkie-talkies are becoming more and more standard for HAM. How to better play the important role of walkie-talkies in outdoor sports, the following questions and answers, learn together:
Q: What kind of walkie-talkie should I buy for walking and climbing?
A: First of all, you should have at least one national license-free intercom (409MHz, 0.5W transmit power, 20 channels), the distance between the city is about 500 meters, and the suburb can reach one to three kilometers for entry. Then, you can consider the license, using the amateur segment (430-440MHz, mill / green field frequency is also in this range) hand platform and platform.
Q: Can I buy a model with 409M and amateur segment in one step?
A: Yes, but don't buy brands or models with unstable performance. After all, the first requirement for outdoor sports communication is: reliable. In addition, these models may not pass the inspection without the committee.
Q: 0.5W/2W/4W, how many call distances do you correspond to?
A: There are many factors that determine the distance of communication. The height, antenna and terrain all affect the communication distance more than the power, so there is no one-to-one correspondence between power and call distance. The design, process and component quality of different brands also affect the power.
Q: Is there any standard for talking on the walkie-talkie?
A: In the amateur section, there are very strict communication standards, and special training will be given when the license is taken. In the license-free 409M, there are the following provisions:
Do not arbitrarily change the transmission frequency, increase the transmission power (including the additional installation of RF power amplifiers), and do not arbitrarily connect external antennas or switch to other transmitting antennas;
Do not cause harmful interference to various legal radio services during use. If harmful interference is found, stop using it immediately and take measures to eliminate interference before continuing to use it;
The use of public walkie-talkies, the quality of their communications is not protected by the radio regulatory agency, and should withstand the interference that other normal working radio services may cause;
It is forbidden to use at airports and aircraft;
It is forbidden to interconnect with public telephone networks, public mobile communication networks and other telecommunication networks.
Q: If you use amateur paragraphs without a license (such as the mill/green field frequency), what will happen?
A: Technically speaking, if you don't have enough knowledge and use amateur paragraphs, you will cause interference to others without knowing it. Legally, equipment and fines may be confiscated, and serious consequences (which may be caused by circumstances that you do not know) are punishable by imprisonment for up to three years. If it violates national security laws at the same time, it will be even more serious. And in the amateur section, if you call without a legitimate call sign, no one will take care of you, because the licensed ham and the unlicensed communication will be revoked.
Q: There are some parallel radios that indicate that they are FRS/GMRS license-free bands. Can they be used domestically?
A: FRS/GMRS is an unlicensed band in some parts of the country, but this band (462-467MHz) has long been classified as other special uses in China. So if you launch at this frequency, it has already interfered with the legal use of others. If you don't want others to interfere with our communication, we certainly shouldn't interfere with the normal communication of others.
Q: How to use the walkie-talkie to call for help in an emergency?
A: The amateur section should call the relay station and maritime SOS channel within 300KM in the distance order, and then follow the standard operation, and will not repeat them. The 409M should be operated as follows:
First collect some mobile phone batteries for backup, so that there is a backup battery after the walkie-talkie battery is used up. Modification is very easy, as long as two metal wires are fine. The whole team only left two walkie-talkies in the power-on state, and all others were turned off to save battery.
Find two players with good physical strength and clear thinking, and bring two walkie-talkies to the highest point nearby (the higher the better, but pay attention to their own safety). One walkie-talkie is on the fifteen channel watch (must turn off the mute function!), another one from the first channel to the 20-channel cyclic call: "SOS SOS here is XX/XXX in a certain mountain emergency call here is XX/XXX In the emergency call of a certain mountain, please receive the signal to the fifteen channel reply, please receive the signal to the fifteen channel to reply to me", the next round of calls after the next ten minutes. If you still haven't responded after an hour, consider moving to a higher and wider location. You should keep listening to the fifteen channels during the move. In the unobstructed mountain top, the signal of the 0.5W walkie-talkie is possible to pass hundreds of kilometers.
Q: What should I do if I receive a call for help on the intercom?
A: In order of importance: first, to ensure the safety of themselves and the team; second, to inform the team to abandon the original plan, to save people as the only goal; third, to establish contact with the outside world, forward the distress signal, serve A bridge of communication between the helpers and the outside world; fourth, to carry out rescue operations wherever possible. The third point is very important. If you have not forwarded the distress signal to the outside world, do not take any action.
Q: Is the headset easy to use? Is the VOX feature useful?
A: The earphones are not suitable for sports with large limbs. It is easy to cause the headphones to fall off and you don’t know them. For sports that need to liberate your hands, such as road cycling, paragliding, you can use headphones, but you must develop the habit of checking headphones at any time. If you must use the earphones, try to let the friends who know the electronics modify the headphone jack so that the earphones and speakers can sound at the same time, reducing the possibility of hearing the call due to the earphones falling off.
The VOX function can judge the strength of the surrounding sound through the microphone level and automatically emit it when you speak, without having to press the launch button by hand. This function is very unreliable in a noisy, multi-person environment, causing frequent launching and not knowing it. It costs electricity and disturbs others. Therefore, it is not recommended to use the VOX function.