dojammer's blog

In this Internet age, everyone has their own mobile phones and other communication devices, which brings a lot of convenience to everyone's life. However, in some special areas, mobile phones and other communication devices have brought a lot of troubles to people, such as: conference rooms, examination rooms, schools, dormitories and other areas, all encounter similar problems. At this time, we can use rf signal jammer, which can effectively block and interfere with the signals of mobile phones and other communication devices, and help special areas solve such problems. So do you really understand what signal shielding instruments are? Let's take a look at the main problems of common signal shielding instruments.

The signal shielding instrument uses a mobile phone to receive the mobile signal sent by the base station, which interferes with the mobile phone signal and the communication base station communication device. These equipment research and development designs are mainly used in conference rooms, examination rooms, schools, dormitories and other areas where mobile signals need to be shielded. After starting, they can deal with threats that affect information security such as mobile phone signals, electromagnetic signals, and base station signals.

2. How does the signal shielding instrument work?

The signal shielding instrument can effectively interfere with the radio frequency in the area, blocking the mobile phone from receiving information, and thus interfere with all communications in the area. The wireless signal is actually like a noise-cancelling bubble. The user's phone will directly lose the ability to send and receive calls or text messages as long as he is within the range of the signal jammer. The ability to receive calls or text messages will be restored after leaving the shielding signal range.

3. So why use a signal jammer?

Proponents of this technology believe that signal jammers are necessary when we cannot follow the generally accepted correct mobile phone standards. Think about the conference room, examination room, school, dormitory, or other quiet train. Most conversations, text messages, and streaming media can be destructive or even terrible.

Remember that signal jammers will not only block the audio and text on your phone, but also interfere with GPS, radar detection, and police equipment radar detection, which may cause more serious problems. For this reason, the US federal government prohibits the sale and promotion of signal jammers in the US market. So if you want to bring some peace and quiet with a shiny new signal jammer, you may just have to settle for headphones.

4. How should the jammer be tested?

You guessed it, the most common symptom of a signal jammer is service interruption. While some apps claim to detect jammers, most of them are unverified and require a working signal to work. Without any advanced military technology, it is virtually impossible for the average user to detect jammers on their phone.

5. How to prevent noise interference?

Mobile phone jammer is not an effective method unless you can actually find the jammer itself (usually looks like a walkie-talkie, cell phone, or wireless landline) and disable it.

Assuming you are technically proficient and can switch the power of your phone, you can also try jammers. But it does rely on the jammer to block complex signals.

If you suspect you will be the victim of a jammer attack, get away. Jammers usually have a range of no more than 300 square meters, so moving away from your current location is usually enough to avoid it.

Most of the common wireless signal jammers on the market do not have power adjustment functions, such as signal shielding equipment used for signal shielding in examination rooms or signal shielding in conference venues. However, there are still some customer groups who hope that the shielding equipment has a power adjustment function. Most of the purpose of this is to avoid shielding the signal range from being too wide, affecting or interfering with other unrelated areas. So, for a signal shielding device with power adjustment function, should it be adjusted overall or by frequency band? What about transmit power?

Looking at this issue from the customer's perspective, customers certainly hope to be able to realize the power adjustment operation of the signal shielding equipment simply, conveniently and quickly. For example, the output power can be adjusted via a physical power adjustment knob. However, such expectations are actually difficult to achieve, and trying to achieve overall power adjustment with a simple knob is basically unfeasible. This is because the wireless signal jammer is divided into frequency bands according to different frequency bands and signals of different formats, and consists of at least ten shielding modules. Each shielding module only interferes with signals within the current frequency band. Take mobile phone signals as an example. For mobile phone signals in different frequency bands and different formats, even at the same location, the signal strength received from the base station is actually different. The result of this difference is that when the cell phone signal jammer targets mobile phone signals in different frequency bands and different formats, the effective shielding distance is also different, sometimes greatly.

It is obviously inappropriate to only use an adjustable potentiometer to adjust the overall power of the signal shielding device. The correct approach is to adjust it separately for each different frequency band. This is why you can see that any wireless signal jammer with power adjustment function has multiple power adjustment knobs, and the number of these adjustment knobs corresponds to the shielding module. The power adjustment of the signal shielding device can control the effective shielding range more accurately, but if the user only relies on the adjustment of the power adjustment knob, only a general effect can be achieved.

In order to avoid being interrupted by the sudden ringing of mobile phones during the meeting, or to allow participants to concentrate on listening to the meeting content, and to prevent the meeting content from being leaked, using a conference room signal jammer is a very wise choice.

Conference room signal jammers suitable for use in small conference rooms. Currently, the market for conference room signal jammers is mainly divided into built-in antennas and external antennas. So, should you choose a conference room signal jammer with built-in antennas or external antennas? Antenna.

For conference rooms with a relatively small area, you can choose a conference room signal shielding device with an external antenna. This kind of external antenna shielding device is often relatively cheap and relatively economical. Let’s not talk about quality and workmanship for now. Some conference room signal jammers with external antennas even have antennas of different lengths. This will definitely affect the overall aesthetics of the conference room environment. Moreover, the cooling fan of the conference room cell phone blocker is If it is exposed to the outside, there will definitely be noise, which will affect the order of the meeting room.

If you choose a conference room signal jammer with a built-in antenna, the antenna cannot be seen from the outside of the shielding device. The antenna is not exposed, and the built-in antenna is also a kind of protection for the antenna. If the conference room signal shielding device with an external antenna needs to be transferred and used, if the antenna is accidentally bumped during the transfer process, the antenna can easily be knocked off. In this way, the machine can no longer be used and needs to be returned to the factory for repair. If you continue to use it, the radio frequency module inside the conference room signal jammer will burn out. If the conference room signal shielding device with built-in antenna needs to be moved, it is very convenient. You can directly grasp the groove handle on the back of the device. It is simple and convenient. Even if there is a slight bump, the internal antenna will not fall off, which can ensure the conference room signal shielding. normal use of the instrument.

To sum up, when purchasing a conference room signal jammer, it is recommended to choose a jammer with a built-in antenna.

A customer asked us: When performing the task of fleet safety protection, what is the interference effect of the vehicle-mounted cell phone signal jammer while driving? Will the actual interference effect be affected by the driving speed of the vehicle?

The above-mentioned application scenarios are usually targeted at government leaders or important VIP customers. They are equipped with a vehicle-mounted mobile phone signal jammer in the fleet where their vehicles are located, starting from the departure of the fleet until they arrive at a safe destination. During the entire journey, regardless of whether you encounter parking, traffic jams, low-speed driving, high-speed driving, etc., the on-board mobile phone signal jammer always keeps working continuously to ensure that the entire fleet, especially important people, are safe and sound. Vehicles can be completely and reliably protected. Prevent and prevent terrorists from detonating roadside bombs, car bombs, etc. through remote controls.

When a vehicle-mounted mobile phone signal jammer is parked (stationary) or driving at low speed, it is relatively easy to detect its interference effect on various signals. However, if it is in a convoy or driving at high speed, its effective interference range will still remain unclear. Change?

Based on our past experience in delivery acceptance and comprehensive testing, the interference effect of the vehicle-mounted mobile phone signal jammer under high-speed driving (vehicle speed ≥ 100Km/h) is slightly lower than the test results when stationary, and the magnitude of the decrease is About 10%~20%, the overall impact is not big.

However, customers need to be reminded that the interference distance and effect of car-mounted signal jammers will be affected by various factors for different signal types. For example: for remote control or walkie-talkie signals, etc., the difference in test results is not big when driving at low speed and high speed. For mobile phone signals of various standards, the difference is more obvious. This is mainly because the interference distance of the vehicle-mounted mobile phone signal jammer to the mobile phone signal is closely related to its distance from the mobile phone base station. When tested in a stationary state, the test results It is relatively stable. When driving at high speed, due to constant passing of base stations along the way, the mobile phone will also switch base station signals due to the distance from the base station and intermittent switching, resulting in the strength of the mobile phone signal always changing. Therefore, when the vehicle-mounted mobile phone signal jammer is driving, the interference distance to the mobile phone will always be in a dynamically changing state.

In the information age, communication technology develops rapidly, and mobile phones have become an indispensable tool in people's daily work and life. However, the widespread use of mobile phones has also created some problems that cannot be ignored, mainly:

1. Mobile phones have become a new channel for leaking secrets. Cell phone jammers can provide necessary security protection for confidential information.

With the development of science and technology, the positioning, tracking and monitoring of mobile phones have become the most important reconnaissance means and intelligence sources for countries around the world. Therefore, as long as you carry a mobile phone in a confidential place, whether it is in use or not, as long as it is in standby mode, it is very likely to cause leakage of secrets, causing serious harm to units or individuals, and even to political parties and the country.

2. Mobile phones have become a new source of noise pollution, and mobile phone signal jammers can maintain the normal working order of the place. With the increasing popularity of mobile phones, the environment in conference rooms, courts, libraries, schools and other places has deteriorated. The noise generated by mobile phones has destroyed the quiet and serious atmosphere of these places and affected people's normal work.

3. Mobile phones have become a new unsafe factor. Mobile phone signal jammers can reduce hidden dangers caused by enterprise safety production. Using mobile phones in gas stations, gas stations, oil fields, oil depots, etc. may cause fires or explosions, and the consequences will be very serious.

4. Mobile phones have become a new means of crime, and mobile phone signal jammers can bring necessary help to social stability.

Some opportunistic people use mobile phones to cheat in exams, and some terrorists and hostile elements also use mobile phones to detonate bombs... Facts have shown that mobile phones have become a tool for criminals to commit crimes on some occasions, which has adversely affected social stability.

Dojammer's mobile phone signal jammer can effectively solve the above problems. As a new type of information security product, it uses electromagnetic signals of specific frequencies to form an electric fence in places that need to be protected, so that mobile phones cannot receive base station data and cannot establish contact with the base station, thereby eliminating the negative impact of mobile phones. Play a safety protection role.

There are several ways to test the effectiveness of cell phone jammers in the examination room. Among them, the simplest and most effective method is to directly test the power, shielding range and other data of the signal jammer in the examination room through a spectrum analyzer. If you do not have professional electronic equipment, you can also use multiple mobile phones, walkie-talkies and other communication equipment with multiple frequency bands and different models to conduct field testing of mobile phone signal jammers in the examination room. This may be a method.

During the test, you can prepare mobile phones of multiple brands and using different operators. After powering on, hold the mobile phone from the position of the signal jammer in the examination room to detect the effective radius of the jammer in sequence from near to far. As the distance between the mobile phone and the mobile phone signal jammer in the examination room becomes farther and farther, it is necessary to check whether the mobile phone has a signal bar display, send messages, and make calls at regular intervals. When checking whether the mobile phone is blocked, it is necessary to make a call, because when you first turn on the signal jammers in the examination room, the signal display on the mobile phone may appear inaccurate, so you can try to make a call. If the call fails, the mobile phone will It is within the interference range, otherwise it means it has exceeded the shielding range. During the test, it is recommended to test the shielding distance of the mobile phone signal jammer in the examination room in multiple directions at the same time, and test whether a certain point is within the working range of the signal jammer in the examination room. Because the mobile phone should be held at that position for more than 1 minute before testing.

Compared with professional equipment, although the results tested through mobile phones have certain limitations, they are relatively easy to understand.

Many customers hope that the 5G signal jammer they purchase has the function of penetrating walls. They even hope that the 5G signal jammer can directly penetrate the interference signal through two walls and still maintain sufficient strength. So, can such expectations be realized?

This requires distinguishing the material of the wall. If the interference signal of the 5G signal blocker encounters a reinforced concrete wall in the transmission path, the interference signal will be almost completely attenuated and reflected. Behind such a wall, the reception The interference signal received from the 5G signal jammer will be very weak, even close to 0. If it encounters a second wall, the interfering signal will be completely attenuated. For example: If there are no mobile phone signal amplifiers installed in the elevator shaft and underground parking lot of the building, there will be no mobile phone signal at all in these two places, because the outdoor mobile phone operator's base station signal cannot penetrate the steel bars at all. Concrete wall.

Let’s look at some other strong materials. If the interference signal of the 5G signal jammer for sale is transmitted during the transmission process, it encounters walls made of wooden boards, or walls made of glass, ABS plastic, etc. These materials are not suitable for wireless signals. The attenuation effect of the 5G signal jammer is very limited. When the interference signal of the 5G signal jammer penetrates these materials, the signal strength error is very small. Even if there are two consecutive such walls, a strong interference signal can still be received.

Based on the above content, the issue of whether the interference signal of the 5G signal jammer can penetrate two walls has little to do with the 5G signal jammer itself, but should focus on the material properties of the wall.

It is a key device that has been frequently used in major examination rooms recently. I believe many people should know the true function of this device. It is a key device that has been vigorously promoted in school examinations and can effectively eliminate and prevent candidates from cheating. , that is today’s protagonist: cell phone signal jammer.

There are now less than 100 days left before the college entrance examination. All candidates taking the college entrance examination are concentrating on preparing for the college entrance examination and striving to achieve good results in the college entrance examination. At the same time, many schools are looking for a batch of higher-performance cell phone jammers to ensure stable order in the examination room, so that those who use illegal means to cheat have nowhere to hide, thereby improving the fairness of the college entrance examination for every candidate.

But what many people don't know is that there is such a device, which may have a serious impact on the effect of the cell phone signal jammer, that is to say, the shielding range. This is an issue that needs to be considered in every college entrance examination examination room in the school. What is this device? It is the operator's base station, commonly known as a signal tower, because if there is a base station near the examination room, it will affect the shielding effect of the cell phone signal jammer. Of course, this means that within a range of 500 meters near the examination room, the signal strength of the signal transmitted by the base station to the examination room will be very strong, so the shielding range of the cell phone signal jammer will become smaller. If the base station is 500 meters away from the examination room, the impact on the cell phone signal jammer will be very small. As for why it causes an impact, this is because when the base station itself transmits signals to the surroundings, it will carry strong electromagnetic signals. As the distance of the electromagnetic signals emitted by the base station increases, the field strength of the electromagnetic signals will also increase accordingly. Reduction, and the field strength of this electromagnetic signal is one of the most important fact

Therefore, in the examination room, before purchasing a cell phone signal jammer, you might as well do an actual test to determine the actual shielding range of the jammer, and then decide how many cell phone signal jammers are needed based on the actual test data. This is very important, otherwise some places will not be blocked. However, no matter whether the cell phone signal jammer will be affected or not, a cell phone signal jammer with superior performance and more professional is a must-have.

The GPS signal jamming system is designed to suppress the signals of the global satellite navigation GPS system in the 1500-1600MHz range. Jammers make it impossible for GPS satellites to monitor the location of cars and all vehicles via GPS, and gps jammer devices will not interfere with cell phones and other devices. The GPS jammer range can be from 5 to 15 meters, which is enough for cars and buses as the trackers are usually installed in the cab inside the car. After initiating the connection via the car's cigarette lighter, the device starts working immediately and generates radio noise (interference) in the range 1500-1600 MHz (L1/L2) within a radius of 15 meters.

• The GPS positioning and navigation system only requires a GPS signal jammer.
• Dual-mode navigation: network positioning (mobile phone signal positioning) navigation + GPS navigation. For this kind of navigation you need GSM GPS jammer.
• Network positioning (mobile phone signal positioning) navigation. For this you need a gsm jammer.
• 4. COMPASS system, GLONASS system and Galileo system.

234 These three systems are rarely used in civilian applications.

GPS devices all require a phone card. The current location information calculated by the GPS module is uploaded to the positioning server by the communication base station through this card for user query. The jammer uses radio electromagnetic waves to interfere with the connection between the card and the communication base station to achieve The GPS location cannot be queried by the user.

• 1. For the HA-1000H high-power cell phone blocker, first confirm the location of the communication base station, find a high point and fix the output port of the machine downward (to prevent rain), and fix the antenna on the top or sides of the machine with poles. Turn your back or side to the base station and let the front face toward the area that needs shielding (the antenna emission angle is 65° horizontally and 13° vertically). The antenna must not face the base station, otherwise it will interfere with the base station and affect the shielding effect;
• 2. Connect each antenna input port to the six signal output ports of the host through a half cable feeder, connect one end of the power cord to the aviation interface to the machine power input port, and the other end of the power cord to the 220V power socket;
• 3. Turn on the power switch on the inner panel of the host chassis and the machine will start working. After the machine starts working, lock the chassis to prevent anyone from turning on or off the machine at will;
• 4. If you need to shield the entire building, the machine needs to be installed at a high point about 20 meters away from the front or back of the building. The installation height of the antenna should be slightly higher than the shielded building, so that it faces 10°-30° downwards. Emit interference signals.

• 1. The HA-1000H high-power cell phone signal blocker must not have the front of the antenna facing the base station or be blocked by obstacles around it, otherwise the shielding effect will be affected;
• 2. Before turning on the computer, be sure to connect the antenna and the output port of the host one by one before starting the computer. Otherwise, the host will be damaged.
• 3. When the equipment is working, avoid long-term human contact within 10 meters directly in front of the antenna.