1. Communication equipment commonly used in general outdoor activities:
The vehicle radio, with a typical power of 10~50 watts, is suitable for vehicle or base use where the power supply is more reliable.
Handheld radio, with a typical power of less than 5 watts, suitable for personal use.
2. Common frequency bands:
VHF frequency band, the typical frequency range is about 136~174MHz, which can be subdivided into high, medium and low three part.
UHF frequency band, the typical frequency range is about 400~470MHz, which can be subdivided into high, medium and low frequency bands.
CB band, the frequency range is about 25~35MHz, which belongs to the short wave high band.
Because the VHF and UHF frequency bands are mainly transmitted in a straight line of sight, “visible and can be communicated” within the largest call range, both parties on the call can choose a high and unobstructed place to get the best call Effect. If the call effect is not good, try moving the position left and right, back and forth, and it will generally improve.
HF high-band diffraction capability is better than VHF/UHF band, and can use ionospheric reflection for medium and long-distance communication between hundreds of kilometers to 2,000 kilometers, but it cannot be the same as V/U band. Reliable communication is fully guaranteed in situations such as mountain blocking.
3. Basic operation of the walkie-talkie:
1. Install the battery and confirm that it is locked with the body.
2. Check the antenna to make sure the contact is good.
3. Power on.
4. To set or check the frequency (channel), the unit and other walkie-talkies in the same team (group) should be on the same frequency (channel).
5. Set the transmit power.
First check whether the battery is fully charged. For example, when the transmitter button PTT is pressed, the transmitter indicator (usually red) flashes, indicating that the battery is insufficient. At this time, using high power to transmit will make the last point of power immediately. When it is exhausted, it is best to replace the battery immediately.
If you can keep in touch, try to use less power to maintain a longer talk time.
6. Adjust the squelch threshold SQL knob to a position where there is just no “rustling” noise. If the squelch SQL knob is adjusted too deep, weaker signals will be missed and the call distance will be shortened, so you should pay attention.
7. Press the transmit button PTT, try connecting with the same team (group) walkie-talkie, adjust the volume at the same time, and confirm that the transceiver can be put into use.
Four. Frequency and Antenna Selection:
The principles are as follows:
Frequency resources are limited, and the frequency allocation is managed by the national radio The Commission has established that the use of communication equipment must comply with relevant laws. The importance of different communication services is different, and there are different usage rights in different frequency bands. When using communication equipment in outdoor sports, you must be careful not to cause interference to other communication services, and do not set the frequency to the in-use frequency of other services.
In the case of not conflicting with the previous one, the frequency is determined according to the model used. Which frequency band the walkie-talkie is in, the frequency is set in that band, and it must be equipped with an antenna of this band (pay attention to the distinction between high, medium and low bands), so as to ensure the highest receiving sensitivity and the highest efficient power radiation output, in order to obtain the maximum call distance. Never mix antennas of different frequency bands, most antennas are similar in appearance but may perform significantly worse.
Commonly used walkie-talkie antennas are divided into short rubber antennas and long rod antennas. Generally, the use of the rod antenna is better than that of the rubber antenna, but it is not as short and portable as the rubber antenna. Conditional can be matched with both, timely selection.
Six, battery and charger:
The battery should choose a large capacity (1000mAH~2000mAH) rechargeable battery to get longer standby and use time . Nickel-cadmium batteries are easy to pollute the environment and have obvious memory effects. It is better to choose nickel-metal hydride batteries. Lithium batteries are generally not suitable for the size of the walkie-talkie battery box (cabin), and are only suitable for those who have the ability to DIY.
From a practical point of view, the battery box that can be opened to replace the battery is the best, and various types of batteries (such as nickel-metal hydride, nickel-cadmium, alkaline, zinc-manganese, usually 5 size), especially when the charging conditions are not available, it can be easily replaced with a non-rechargeable ordinary battery, which is the biggest advantage of the battery box.
The performance of the battery will be degraded when exposed to low temperature (eg -20 degrees), and the usage time will be shortened or even unusable. In alpine areas, special attention should be paid to keeping the battery warm. The easiest and most effective way is to put the walkie-talkie in your arms and use your body temperature to prevent the battery from being affected by low temperature. The spare battery should also be carried in the arms.
The charger is divided into fast and slow, automatic and normal. It is recommended to use automatic fast charging that matches the total voltage (or number of cells) of the rechargeable battery of the walkie-talkie. The charging time is short. The typical charging time for a 1500mAH battery is no more than 3 hours, and it will automatically transfer to trickle charging when fully charged. Does not damage the battery. Usually, the typical charging time for a 500mAH battery is about 15 hours with an ordinary slow charge, which needs to be taken care of. Now the battery capacity is getting bigger and bigger, it takes too much time to charge slowly.
It is not suitable to fast charge the battery at low temperature, and it should be done after taking heat preservation measures.
7. Basic contact:
The call should be concise and standardized. Nonsense or ambiguous words, in addition to wasting limited power, it is also easy to make mistakes, especially in emergency situations.
In the communication, a “full stop” should be added after a paragraph (especially a large paragraph) to avoid “collision” between the two parties, and as a result, no one heard what the other party said.
Speak more than a second between the two parties so that others can jump in when they are busy. Important content should be repeated to avoid errors.
Make an appointment for the next call.
For example:
“ST, BC (call)”
After one second interval…
” ST received, please tell”
……
“How are you now?”
……
“We’re doing fine. We’re going to leave early tomorrow morning at 5 am, repeat: 5 am tomorrow morning,
Please speak.”
……< /p>
“Yes, I agree to leave at 5 o’clock tomorrow morning, be careful, please speak.”
……
“Okay, thank you.”
……
“Okay, I will call you again at 5:00 tomorrow morning. ST, (here is) BC, the call is over.”
. …..
“BC, (here) ST, see you tomorrow, over.”
8. Some frequencies and suggestions that may be useful :
145.000MHz and 433.000MHz are international emergency frequencies, anyone can use these two frequencies to call for help in an emergency. However, it is a dedicated service frequency in peacetime, and users without a radio station license cannot occupy it.
FRS public walkie-talkie (such as Motorola’s 0.5-watt toy walkie-talkie) frequency table (unit: MHz):
409.7500 409.7625 409.7750 409.7875 409.8000
409.8125 409.8250 409.8375 409.8500 409.8625
409.8750 409.8875 409.9000 409.9125 409.9250
409.9375  ; 409.9500 409.9625 409.9750 409.9875
(20 frequency points in total, channel spacing: 12.50kHz)
It is recommended that FRS users use the Channel 409.8500 as the calling channel. Special reminder, FRS walkie-talkies generally have sub-tone selective calling function, it is best to disable it, otherwise it may not be able to communicate with other walkie-talkies on the same frequency.
It is recommended to agree on several nationally unified frequencies for outdoor activities, such as N frequency points (channels) for VHF and UHF. The current walkie-talkie generally can set at least 8 channels, each team (group) chooses one, the probability of 8 teams using the walkie-talkie at the same time in one place is very small, but the probability of having two or three teams is relatively large. The specific method is to learn about the frequency of use of each team (group) in camps such as BC, or to clearly indicate the frequency used by the team (group), so that members of the same team (group) cannot be called when the terrain is blocked or other teams can pass through the accident. The walkie-talkies of (group) do manual transfer in order to obtain the greatest degree of communication guarantee.
9. About extending the use time of the walkie-talkie:
The current battery capacity of the walkie-talkie can generally stand by for more than ten hours to more than a day, but frequent calls or High-power transmissions can drain the battery in half an hour to two hours. Use large-capacity batteries as much as possible; on the premise of maintaining normal calls, try to choose the smallest transmit power; when you are active in low-risk areas for a long time, you can start regular contact, such as every half an hour or five minutes before and after an hour. Contact, other times shut down to save power, but in high-risk areas activities should try to keep the whole process turned on.
Which frequencies do you usually use in outdoor activities? For communication, I usually use 438.000MHz.
If there is anything wrong in the text, please correct it.