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---- understand the radio from here onwards (airwaves pass the love of the database) (/bbs/dispbbs.asp? boardid=14&id=91)
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-- By admin
-- Author. p>-- Published: 2005-6-28 8:59:23
-- Understanding of the radio from here on out (airwaves to pass the information base)
Heh, after a period of time to collect information is finally done, I hope you will be useful to you! This is to facilitate you to find information and come up with a method, the purpose is to serve as a database.
The new solid top theme of the current organization is based on the use of forum software related to do a connected post and facilitate access to relevant information, divided into the novice, HAM Friends history and related, laws and regulations, the essence of this version. Radio technology, equipment manuals, equipment introduction several items. Each post as a project. I am in accordance with the wind catching car shadow moderator August sister to do the connection form and post (I would like to thank the August moderator to give me inspiration), the difference is that this post is used in all the super connection as long as the direct click on the text to open the topic.
Because this version of the temporary related articles is not a lot, so can only gradually improve. Welcome to publish some good articles to organize into the theme of the post, if you do not do enough please point out, I am only a computer illiterate understand not much can do only this, hope to understand the puppet!
This post does not have a reply. If you have any questions, please open a new post, that there are articles need to be added to the text message notification, I will promptly update!
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-- By admin
-- Posted: 2005-6-28 8:. 59:55
--
Common knowledge of walkie-talkies:
How far is the talking distance of a walkie-talkie? Conventional walkie-talkie communication distance can reach up to 8 to 10 kilometers in the open land, and up to 3 to 5 kilometers in the general urban area, and the call distance will be relatively shorter in the case that there are tall buildings or mountains blocking the way. When there is network support, walkie-talkie range up to dozens of kilometers. Networking is the use of repeater (also called base station or relay station), automatically receive the transmitted signal from the walkie-talkie, and amplify and forward it. Networking can be large intercom communication coverage, extending the call distance, open space up to 10-20 kilometers (handheld radios) or even 30-50 kilometers (car radios), the building can be covered in the basement, underground parking lots, fire escapes and other shielding is serious, usually known as the dead zone of the region.
Can mass consumers buy walkie-talkies? The general public can also buy walkie-talkies, but before the purchase and use of walkie-talkies must be applied to the local radio management committee (referred to as "no committee"), receive a radio license and pay the frequency occupation fee. From December 6, 2001, China's opening of the civilian walkie-talkie market, the use of 400MHz, transmit power less than 0.5 watts of civilian walkie-talkie, without having to go through any formalities.
Can walkie-talkies make phone calls? Under the condition of network support, walkie-talkies can be used to make phone calls. However, if it is only a regular call between individual handsets, it cannot be used to make a phone call.
Common sense of walkie-talkie use:
Antenna use precautions 1.
2, the walkie-talkie antenna can not be unscrewed, otherwise it is easy to burn out the power tube when transmitting.
3, do not use the damaged antenna. When transmitting, if the damaged antenna touches the skin, it may cause please slight burns.
Precautions for Battery Use 1. You should use the original or approved battery.
2. All batteries may cause damage or personal injury if metal conductors such as jewelry, keys, or beads practice touch the exposed electrodes of the battery. Please be careful with a fully charged battery, especially when carrying it in a pocket, wallet or other metal container.
3. Charging should be performed at 5~40 degrees Celsius. If the temperature exceeds this range, battery life will be affected and there is a possibility that the battery will not be charged to its rated capacity.
Electromagnetic Interference/Electromagnetic Compatibility To avoid problems caused by electromagnetic interference and/or electromagnetic compatibility, turn off your walkie-talkie wherever it is labeled with a "turn off walkie-talkie" sign. For example, in hospitals or other places where healthcare medical equipment is used. You should also turn off your walkie-talkie on request when traveling on an airplane.
Precautions for the operation of the walkie-talkie:
When the walkie-talkie is transmitting, keep the walkie-talkie in a vertical position and keep the microphone 2.5-5 centimeters away from the mouth. Keep the walkie-talkie at least 2.5 centimeters from your head or body when transmitting. If the handheld walkie-talkie is carried on the body, keep the antenna at least 2.5 centimeters from the body when transmitting.
2. Do not perform multiple power-on and power-off actions during use, while adjusting the volume to a level suitable for your hearing.
Safety precautions for the use of walkie-talkies 1. In cars with airbags, do not place the walkie-talkie within the range that may be involved when the airbag is deployed. If the walkie-talkie is in the area that may be involved when the airbag is deployed, once the airbag is deployed rapidly, the walkie-talkie may hurt the people in the car with the great impact.
2. In potentially explosive atmospheres or situations, turn off the intercom unless it has been specially certified. In potentially explosive atmospheres, electrical sparks can cause an explosion or fire.
3. Do not replace or charge the battery in a potentially explosive atmosphere. Installing and removing the battery may cause contact sparks and result in an explosion.
4. Turn off the walkie-talkie before approaching blasting areas and areas where detonators are located to avoid possible explosions.
Routine maintenance of the walkie-talkie:
The pushbuttons, control knobs and the case are easily soiled after long-term use of the walkie-talkie, please remove the control knobs from the walkie-talkie and clean the case with a neutral detergent (do not use strong corrosive chemicals) and a damp cloth. The use of chemicals such as stain remover, alcohol, sprays, or petroleum agents may cause damage to the surface and housing of the intercom.2. Hold and place the intercom gently, and do not move it with the hand-held antenna.3. Cover the dust cover (if equipped) when accessories are not applicable.
Intercom Technical Assistant:
Can't talk to other group members in the group?
First of all, please make sure that the frequency and subaudio signal you are using are the same as the other members of the group; if there is no problem, please make sure that the other members of the group are in the service area.
The voice of other group members appears in the channel? Please change the subaudio signal tone, and you must also change the signal tones of all the radios in the group, or apply for a frequency change.
How long will the battery last after charging correctly? The battery has reached the end of its life, please renew the battery. (Ni-MH batteries are normally charged and discharged 500 times for normal use, and Li-Ion batteries are 1000 times.)
The intercom is not scanning? The channel is not included in scanning when programming the intercom (set by a professional) or the scanning function of the whole machine is turned off.
Full band noise after programming? The squelch is turned all the way on when programming the intercom. Non-professionals are advised not to adjust the function parameters.
Regular beeping after programming? The intercom was programmed incorrectly. The frequency programmed is out of the frequency range specified by the intercom or the selected model is not paid with the machine.
No sound after using the headset for some time? The earphone socket of the walkie-talkie is bad. Send it to a service station for repair.
Talking distance becomes close to poor sensitivity? Check whether the antenna is intact, whether the antenna holder is loose or damaged (yes, please send it to the repair station for repair).
Can the walkie-talkie receive the other party's speech but can't transmit? Check the PTT button. Send it to the service station for repair.
Can't turn on the radio or often power off? Check if the walkie-talkie battery contact is deformed or broken.
No display or wrong display on walkie-talkie with LCD? The walkie-talkie has been dropped or used improperly resulting in bad LCD or poor contact of conductive rubber (send it to repair station for repair).
The other party to receive the sound is small or voice intermittent? Check whether the small hole at the intercom MIC sending is blocked (No, please send it to the maintenance station for repair).
Receive intermittent and accompanied by large noise? The intercom has reached the limit of communication distance or there is a tall building blocking the basement, etc. (No, please send it to the service station for repair).
How to deal with the water in the machine? First dismantle the machine, disassemble all external parts one by one (such as buttons, PTT rubber, light guide column, etc.), use anhydrous alcohol or special washboard water to clean the circuit board carefully, dry, use small tools to clean up the stains on the circuit board; and then soak in anhydrous alcohol, conditions can be used to clean ultrasonic cleaner; secondly, fish out the dry with a hairdryer (pay attention to the temperature can not be too high), and inspect the circuit board Whether there are injuries, if there is a broken line to use a fine enameled wire for coupling, with a triple meter to measure the board's power supply positive and negative extremes of the resistance value, can not be short-circuited or disconnected (energized, check the current, the normal 40MA or so, the launch of the launch of not less than 1,000MA); Finally, check the wireless port is dirty, such as dirty and cleaned up, at the same time, if there is any other failure to overhaul the routine. The circuit corrosion is serious into the water machine generally can not be repaired, so the machine into the water should be disposed of in a timely manner.
Testing common problems in the treatment of 1, frequency interference: in use often have a series of frequency or receive other radio noise, interference with the normal use of walkie-talkies, there are three ways to deal with it: ① change the frequency. ② Add subaudio or DTMF, etc.. ③ reduce the level of squelch (under the same conditions as the individual machine to receive interference when applicable)
2, the distance is close: walkie-talkie in the communication distance and the actual need for the difference of a few meters, you can adjust the machine power and squelch the level to achieve. After adjusting the still can not be improved in the consideration of installing a transit station to solve the problem.
3, sound intermittent: walkie-talkie communication in the critical distance is often found in the intermittent phenomenon, at this time you can adjust the level of squelch or cancel the reception of subaudio to test the effect.
Four, whistling: in the distance of only a few meters or closer when the two walkie-talkie communication will occur whistling. This is a normal phenomenon, the sound can be turned off to the appropriate size to solve.
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-- By admin
-- Published: 2005-6-28 9: 00:40
-- Time: 2005-6-28 9: 00:40
-- Author: admin 00:40
--
The simple concept of radio (car radio/hand radio) and the purchase of a brief description
Car radio/hand radio is a radio, we usually say that the walkie-talkie is actually a radio, in the name, there are usually a lot of misunderstandings, for example, many people think that "walkie-talkie" is a pair of use, or think that "walkie-talkie" is a pair of use, or think that "walkie-talkie" is a pair of use, or think that "walkie-talkie" is a pair of use. For example, many people think that "walkie-talkies" are used in pairs, or think that "radio" is such an esoteric thing, but in fact it is very easy to understand - including the radio part of the stereo installed in your car, and the radio of the Walkman, in fact, they are all a big class of things, translated into English, they are all called "RADIO". RADIO, except that the radio we're talking about is usually a conventional communication tool that combines both receiving and transmitting functions and can be used to transmit radio signals to communicate with other people.
I won't say much about radios, I don't know much about them.
1, what is radio?
Frequency/frequency point/channel, can be briefly said
Think we usually listen to 97.4 103.9 MHz, is the frequency, said frequency point may also be right, said the channel is a bit far-fetched, but often said "103.9 channel, 97.4 channel", is a little bit of The first time I've seen this, I've had a chance to talk to you about it.
In fact, we listen to the radio every day is the radio, but that is the "radio station" transmitter, the radio station power is crazy big, transmitter antenna location is crazy good, the coverage is crazy wide, so in its coverage of the receiver (that is, the radio) can receive its signal, and converted into sound to play out.
Now imagine that you and your friends have a radio receiver, a "miniature radio station" (radio transmitter), the one we're talking about (Radio Tranciver?). Anyway, the word was coined. They transmit and receive at the same time, so they can talk to each other.
2, frequency / frequency / band
97.4MHz is the frequency of the music station 103.9MHz is the frequency of the traffic station 438.500MHz is the transmission and reception frequency of the Beijing amateur radio enthusiasts can be legally used (400MHz band, and then the other bands also have amateur HAM legal frequency, not to mention here).
Obviously, everyone's FM radio does not support more than 430 megahertz Receive (as if the FM part of the 86 ~ 107MHZ), so if you want to transmit and receive signals on the 438.500MHZ frequency, you have to have a special equipment, that is, the need for what we usually say, "support for amateur bands of the car radio / hand station / base station" and so on
There are also other bands that are legal for amateur HAM. / base station" and so on
If 438.500 is the frequency, then it is at the same time belongs to the 430MHZ band, we probably 430.000-439.999 is called the amateur 400M band, also known as the amateur 70CM (centimeter) band (is the wavelength of the statement), because this band is mainly allocated to amateur radio enthusiasts to use.
Junior HAM contact more may also be often referred to as the "2-meter band" or "140 megahertz amateur band" is between 144.000-145.999MHZ, is also a HAM can be used in the frequency range. The frequency range that HAM can use.
3, amateur radio/professional radio/radio and the difference between the simple concept
Radio is not much to say, used to listen to other transmitting stations to transmit signals, the usual radio and frequency modulation (FB) / amplitude modulation (AM) two parts, is two different modulation, corresponding to the radio station, there are these two modulation, we commonly support the 430MHZ band of the modulation of the HAM. 430MHZ band of FM radio, and air traffic control is used between 110MHZ-130MHZ frequency, using AM modulation.
And then there is a simple difference between "amateur radio" and "professional radio"
There is a layer of meaning that says
Amateur radio is a radio station that supports the amateur frequency band - supporting (including) 430-400MHZ. -The professional radio is a radio that supports certain other specific bands
Another implication is that the functionality of an amateur radio station is focused on "playing around" with the various parameters involved, including adjusting the transmit power/searching for signals/storing a number of different frequencies.
Another layer of meaning is that the function of amateur radio focuses on "playing", adjusting all relevant parameters, including adjusting the transmit power/searching for the frequency of signal/storing several different frequency points/changing the stored frequency points manually at any time/adjusting different squelch values/signal strength meter, etc.
On the other hand, professional radio focuses on the stability of the use of the radio, so the complexity of the operation is relatively low, while the durability of the battery and the stability of the transmit power performance requirements of the radio.
In contrast, professional radio stations usually can't adjust the transmitter power at will / don't have the function of searching for frequencies / can store a small number of frequencies and can only display the channel number but not the value of the frequencies / need to use a computer and special software and cables to adjust the frequency stored in each channel and the related functions / usually don't have a signal strength meter
And, the professional radio stations may also add some features such as FM and other features in their design
And, the professional radio stations may also add some features such as FM and other features in their design.
And professional radio stations may be designed with additional security measures such as FM, or support for trunking (I don't know much about this)
You think of traffic JCs, armed JCs, or whatever, and they take a station, know which is the on/off volume switch, which one to press to talk to, and screw it to the point where a few channels are for the squadron, and a few are for the main channel, and that's that, and then it's done, and if you take a fancy amateur radio station to the JC, you make sure that he'll be dizzy.
4, the repeater (Repeater) / differential frequency (OFFSET) and direct send
Maybe some people will ask what is the "repeater",
This if we talk about the details of the wave may be said to be bypassed and so on, I'm a little bit dizzy, as early as the physics teacher back to the teacher, let's say that in the high ground, there is one or a pair of antennas and a special antenna. There is an antenna or a pair of antennas and a special transceiver radio that is responsible for forwarding signals received on one frequency to another, so that stations in its coverage area can contact it, that is, contact other people through it.
And dizzy?
To put it this way, 2 stations on the ground may not be able to transmit to each other due to buildings/terrain etc., but 2 people and this very high, well-positioned repeater can both communicate well, so everyone achieves a wider coverage area through the repeater, helping to amplify the signal of low-power devices.
The usual repeater needs to use a pair of frequencies, one to receive the signal from the user's handheld or car station (uplink signal, such as 434.750 in Beijing), and when received, broadcast out on the other frequency (downlink signal, such as 439.750 in Beijing). Since the repeater must occupy a better geographic location and may have a higher transmitter power, more people can be reached through the repeater.
OFFSET
The difference between 439.750 (the user's listening frequency, the downlink frequency) and 434.750 (the user's transmitting frequency, the uplink frequency) is the OFFSET, and we can see that the transmitting frequency is the receiving frequency minus 5MHZ (-5MHZ), so it is called "downlink 5MHZ". 5MHZ".
For some stations, you can set the uplink frequency and downlink frequency directly and then save them to a channel for easy use.
For some stations, you can set the receive frequency first, then set the value and direction of the differential frequency, and then save it to a channel.
The setup method doesn't matter, as long as you understand the repeater/differential frequency concept, the rest can be solved by reading the manual of the device. I won't go into that here.
DIRECT TRANSMITTING
Usually stations are transmitting and receiving on the same frequency, and the user switches between receiving/transmitting state of the station by using the PTT (PUSH TO TALK) button, pressing the button to talk and releasing it to listen.
Receiving and transmitting on a single frequency is what is called "direct transmission", for example, 438.500 438.550MHZ is the more commonly used direct transmission frequency for amateur radio in Beijing.
Of course, on the same frequency, only one device can transmit at the same time, and the other device receives, if at the same time two people are transmitting, their signals will interfere with each other, and will not be able to hear.
4, the car world commonly used amateur radio station to buy points
Don't be superstitious MOTO 6200C and some foreign production FRS (FAMILY RADIO SERVICE) home small radios, that is simply a toy!
To avoid the interference of the transmitting equipment to other frequencies, the power of these products must be less than 0.5 watts, and may be able to reach a direct distance of 2 kilometers in the absence of cover, if in the urban area, 1 kilometer is already good. The only advantage is that you don't need any license and inspection, you can buy and use them at the same time.
Of course, these small handset are fixed channel fixed frequency transceiver equipment, can be understood as "low-power / non-adjustable frequency professional radio (home)", of course, their frequency is fixed at 409. MHZ (imported) range, usually with only 16 fixed frequencies that cannot be changed. It's possible to make a direct transmission link to other amateur stations if they support these frequencies, but obviously these little toys can't make a link to the HAMs.
If you want to choose a radio station, you must meet the following conditions:
★The frequency range covered must support (and include) 430-440MHZ
★Must have a differential function
★It is recommended that you choose a machine that can be hand-configured (that is, one that allows you to select the frequencies directly and store them in the channel without the need for a computer to write the frequencies)
★It is recommended that you choose one that can be hand-configured.
★It is recommended to support the sub-tone function
★It is recommended that the power is more than 25W (car radio) / support for a maximum of 5W (hand radio), in order to ensure that the distance of the pass-through connection.
With the above conditions, you can step into the ranks of amateur radio enthusiasts (HAM) (of course, you must also apply for the relevant legal procedures)
Common Radio Selection Reference
(The prices listed are for reference only)
Parameter Explanation
Frequency range: 144-146 / 430-440 MHz Frequency range
Frequency range: 144-146 / 430-440 MHz Frequency range
Frequency range: 144-146 / 430-440 MHz 430-440 MHz Frequency range
Mode: FM operating mode
RF Power output: Hi: 2.5-6/2.2-6 W, L 0.5 W, El: 50 mW Various RF outputs (power)
Voltage: Max 13.8 VDC operating voltage
Current drain: ? Current drain: ? Current drain: ? mA Operating current consumption
Impedance: 50 ohms Impedance
Dimensions (W*H*D): 54*112*33.5 mm (with PB-38) Appearance Specifications
Weight: ? Kg Weight
Regarding the radio's range:
The radio's range is affected by many factors, such as the radio's transmitting power, receiving sensitivity, metal shielding of the vehicle body, the surrounding environment, the blocking situation, the height, the type of antenna and antenna with the machine matching condition, and even the air temperature and humidity, etc., and any of the so-called "talk distance" can only be used as a reference. Any so-called "call distance" can only be used as a reference. For example: I once used KENWOOD F7E handheld 0.5 watts of transmitter power (equivalent to the market MOTO6200C WALKIE-TALKIE maximum transmitter power) in Xiangshan with Tianjin's BG3AAX and other HAM pass-through connection, and in the basement, the maximum power of the 5W transmitter, the ground is less than 200 meters away, it has not been received. WALKIE-TALKIE's so-called 2-3km "talking distance" is actually a reference value for a flat, unobstructed surface, and if you use it in the city, inside a building, etc., you may be able to connect to a distance of less than 1km.
The range figures below are for everyday use in urban environments only. For more details, please refer to the following section for more information.
★Entry-level handheld
Price range 300-400RMB Frequency range: 400-470MHZ (400M band) No mute function Transmitter power: 2W about General urban transmitter range reference: 1-3 kilometers
Better than the entry-level DX for the FB location around the link, convoys travel to keep listening
KINGTON 3118 260RMB (no ready-made picture, please FB look at other DX station, or who has a ready-made send up)
LINTONG 71-B 300RMB
LISHENG 71-B 400RMB Whether this model has a sub-tone function is not known
BFDX 5118, 5118A ( A with sub-tone, the price of about 300RMB)
71B appearance can be referred to KENWOOD 71A, but the workmanship is more crude, the definition of the function keys is not the same, the internal software is completely different from the KENWOOD 71
★★Commonly used FB-class handheld
Maximum transmit power 5W General urban range of reference: 2-5 km
KENWOOD 71A
140M/400M dual-band transmitter handheld
Price: Approx. 1600RMB
References and Pictures:/kenwood/thg71e.htm
Main Features:
Expandable Frequency Range: 140MHZ / 400MHZ Transmitter. 100MHZ-1000MHZ receive
It is a more mature model, which can be said to be the preferred model for hand stations.
★★★★Burning bag level handheld
Maximum transmit power 5W General urban transmission range reference: 2-5 kilometers
KENWOOD F6A
140M/220M/400M three-band transmitter handheld
Price: about 2700RMB
References and images:/ kenwood/thf6a.htm
Main features:
Can listen to 2 frequencies at the same time and transmit on one of them
0.1-1300MHZ reception, full modulation mode
But it is said that 220M transmission is not very useful, other than that, it is not much different from F7E.
KENWOOD F7E
140M/400M Dual Band Transmitter Handycam
Price: about 2900RMB
Reference and Picture:/kenwood/thf7e.htm
Main Feature:
Mainly, you can listen to 2 frequencies at the same time, and transmit on either one of the frequencies
0.1-1300MHz.
0.1- 1300MHZ Receive, Full Modulation Mode
YAESU 5R
50-54 / 144-146 / 430-440 MHz Tri-band Transmitter Handycam
Price: N/A
References and Pictures:/yaesu/vx5r.htm
Main Features:
With 50-54MHZ emission, but not very significant for DX that does not involve HAM, not much exposure to this station.
YAESU 7R
50-54 / 144-146 / 430-440 MHz tri-band transmitter handheld
50-54 / 144-148 / 222-225 / 440-450 MHz (USA version)
Price: 3600
References and pictures: /yaesu/vx7r.htm
Key features:
Fully waterproof, essentially the highest price among handhelds.
★Entry-level car radio
Maximum transmitting power 35W General urban area transmitting range reference: 5-10 kilometers
ADI 446
Taiwan-made 400M single-segment car radio
Price: about 1600RMB
References and pictures: /adi/ar447.htm
Main features:
Functionality is relatively full, the frequency range is only 430-470MHZ, for the car altar DX out FB, enough.
There is a saying that ADI446 hand squinting wire head love bad, I hope the manufacturer has noticed this problem.
(Can not be purchased on the market)
KENWOOD 461
400M single-segment station
Price: about 2000RMB
References and pictures: No
Main features:
Has been the mainstream of the 400M amateur
Reasonably full-featured.
The frequency range is 400-470MHZ,
But according to the news, now can not be set to the factory is 400-470 machine, most of the 461 is through the "open frequency" to 400-470 expansion.
(It is still possible to buy a full-range M2 machine, but the price is about 200 more than an open-range one.)
★★★FB Class Car Desk
I-COM 207H
140M/400M Dual Band Desk
Price: unknown
References and Pictures:/icom/ic207h.htm
Currently not available for purchase.
YAESU 90R
140M/400M Dual Stage Platform
Price: 3000RMB
References and Pictures:/yaesu/ft90r.htm
Main Features:
Currently the smallest dual stage platform in the world
(Not much on the market)
(Not much available) Not very common)
★★★★Burning bag level car radio
I-COM 2720
140M/400M dual-segment car radio, dual-band point guard listening
Price: 2900RMB
References and pictures: /icom/ic2720h.htm
Key Features:
The main features:
YAESU 8900 /yaesu/ft8900r.htm
Kenwood TM-V708 /kenwood/tmv708.htm
Kenwood TM-V7A /kenwood/tmv7e.htm
Kenwood TM-D700A / kenwood/tmd700a.htm
Other stations can be found at www.RIGPIX.COM , .
Added:
The radio models recommended by the World Car Club:
Handheld entry level:
PX: PX388, priced at around 310 RMB. Characteristics: 430 single-segment, transmitting and receiving sound reproduction is good, available cigarette lighter to take power.
Handheld commonly used FB level:
Kenwood 71A: price of about 1600. Characteristics: 144/430 dual-segment models, monitoring, launch, mature models.
Kenwood F6A: price of about 2700. Features: 144/220/430 three-segment model, dual-segment simultaneous monitoring, transmitting, 0.1 - 1300HZ full range of listening. Lithium battery, full AM, can receive FM radio signals.
Car radio entry-level:
Kenwood 461A-M2, the price of about 2000. Features: 430-band manual FM, classic model.
Car radio FB level:
ICom2720, price: 2900 or so. Features: 144/430 dual-segment monitoring, transmitting, manual FM.
Icom208H, price: 2900 or so. Features: 144/430 dual-band, extra large transmitter power, U-band 50W.
Yaesu 7800, price: around 2500. Features: 144/430 dual-segment, extra-large transmitter power, U-band 40W.
Yaesu 8900, price: around 3500. Characteristics: 4-segment car radio with shortwave.
Kenwood V7A, price: 4300 or so. Features: 144/430 dual-segment monitoring, transmitting, manual FM. Extra large blue backlit screen, 280 storage channels. Five in one easy to operate function.
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-- By admin
-- Published: 2005-6-28 9:. 01:09
--
Tips for using walkie-talkies
Talkie-talkies, which are used for communication between team members in outdoor activities, are very effective in places where cell phones do not have signal.
The power of the walkie-talkie and the communication distance:
The power of the civilian walkie-talkie is generally 0.5w, and the communication distance is 3 kilometers ideally, and the actual effective communication distance will be shortened in the environment where there are obstacles in the building. This type of walkie-talkie is characterized by its compact size and light weight, which is suitable for small-scale communication and team outdoor activities, without any communication cost, saving money.
Professional walkie-talkie power is generally 2w, communication distance of 10 km, 3 km in urban areas;
Of course, all theoretical, but once in Bogda base camp, a police walkie-talkie with moto, actually clearly hear the conversation down the mountain: "bring them to the bureau", let me out in a cold sweat.
Typical models of walkie-talkies:
Motorola's, there are t6200c , Mickey-type/princess-type, t5428, t5308 and other models, are civilian 0.5w, and there are also models of bell, haofa, kenwood and so on. But the hottest is a few models of Motorola's civilian machine, compact, cheap, and is a civilian band, do not have to do the formalities. One of them is the 6200c, which is even in line with the public band opened by the national no commission.
The price of the walkie-talkie:
Motorola's several prices in the 300-500 or so, I bought the bell 99160, is more than 100, 2w more expensive, to 600-2000. mainland many mountain friends to buy Motorola's civilian machine, light, cheap, you can use the battery, not like our Xinjiang people still have a lot to do. I'm not sure how much I'm going to be able to get out of this, but I'm sure I'm going to be able to get out of it.
Frequency of the walkie-talkie:
The walkie-talkie generally has 10-20 call channels, as long as in the same channel can talk to each other, no matter how many stations. If a channel is not clear or there is interference, you can discuss, switch to other channels. Don't forget to negotiate. If one channel is switched and the other isn't, you're blind.
The public frequency opened by the National Commission for the 409mhz within the 20 frequency points, Motorola's 6200c is this band, so you can sell in the cell phone store openly. There are also a lot of walkie-talkies that use foreign frs (home walkie-talkie) specifications, such as the bell 99160 I bought, which operates near 462mhz and 467mhz.
Despite the fact that the frs frequency doesn't meet the domestic specification, no one cares if you buy it because it's only 0.5w, but you can't communicate with Motorola's 6200c, so when you're out and about and there are more walkie-talkies, try to see if you can get through to each other first.
Remember, the walkie-talkie call is simplex (unlike the telephone is duplex), you if you have been pressing the button, occupy the channel to speak, other people will not be able to say. That's why walkie-talkies are popular for text-based conversations, one for you, one for me.
Batteries for walkie-talkies:
Professionals use rechargeable batteries, like cell phones, nickel-metal hydride or lithium; civilians use ordinary batteries with more, aa or aaa, usually 3 to 4, you can also use rechargeable aa or aaa.
Based on the experience of the outdoors, a set of batteries for the life of the general for the two daytime, that is, about 20 hours. That's why it's common to see people with walkie-talkies yelling at everyone to turn them off as soon as they arrive at camp. It's best to go with rechargeable batteries, invest more at one time and it will slowly become more cost effective, or else you'll have to hitch up 4 NFBs for one event.
The use of walkie-talkies:
General outdoor activities, more than a dozen people, with 2-3 walkie-talkies is enough, the captain of a, a scouting one, a guard, more than the reverse mess. The more walkie-talkies you have, the more you turn into microphones and karaoke, and then let some songbirds take them, the worse.
Some people think that walkie-talkies are useless in the outdoors, I disagree. The most important role of the walkie-talkie is to enhance the confidence of the leader and the whole team, to know whether the road ahead is good, to know the back team to pull away from the players, you can control the rhythm, for the whole team to march happily is very important.
The walkie-talkie should be used in a dashing way, and you have to master some walkie-talkie language, taking into account the walkie-talkie simplex way of working, in addition to the signal in the field is not very stable, you should try to simplify the complex statements, and you have to use Putonghua. Ever heard of Hou Baolin's comedy?