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GPS Signal Jammers and Their Frequencies

GPS frequency blockers are small useful devices that can definitely be useful to many people, whose main function is to block signals from GPS tracking devices. If you are worried that someone might be following you via a GPS tracking device, or you just want to have a GPS jammer on hand in case you might need it, then you should learn something about these devices.

One of the main things that you should pay attention to when buying a GPS signal blocker is the frequencies with which it works. Usually GPS trackers work with GPS L1 frequency, but sometimes they may involve other frequencies, so it is very important that you should know the operating frequencies of the device. The reason for this is the fact that GPS jammers block certain frequency ranges of satellite tracking (GPS L1, L2 and L5) in order to drown out the signals of tracking devices. Thus the jammer you are using must block the frequencies used by the GPS tracker. There are hundreds of different jammers of GPS signals that are available on the market, so it will not be difficult for you to find the jammer that will meet your requirements and wishes.

There are many types of GPS jammers – some of them jam only one frequency, but others are able to block all three at once. Of course, there are also high-end models that can block almost any satellite tracking signals (3 frequencies GPS, GLONASS, Galileo, Compass, etc.), and they are the best choice if you want to be absolutely sure that you are not being watched through satellites. However, these devices can be quite expensive, so you have to decide for yourself how much you are willing to spend on these small gadgets. I assure you that you will not be mistaken if you decide to spend more money on the GPS jammer – this is the purchase that is worth every penny invested in it, because this is the best way to be safe from hidden satellite tracking of your location.

GPS jammers have various characteristics – battery capacity, supported frequencies, etc. However, the most important are the frequencies with which the device works. Although battery capacity is also an important feature, you should carefully look at it if you plan to use this jamming device for a long time. If you want to protect yourself from a specific GPS tracking device, then you just need to choose a device that blocks GPS signals and other frequencies involved(such as GSM/GPRS or even 3G), because all you need to do is find out the frequencies of the tracking devices, and you will have all the information you need to make the right choice.

GPS jammers can also be of different sizes – some of them are more bulky, while others are portable. So if you want to keep your GPS silencer private, then you should opt for a portable device that you can easily hide under your clothes. Bulky devices usually have a larger battery, so they are harder to hide and yet they are the best option if you plan to use them in your car. DO NOT forget that you cannot put a price tag on security, and the GPS jammer is one of those small devices that can provide you peace of mind. No matter how much money you spend on this device, you can be sure that it is worth every cent and will work for the benefit of the security of your personal life!

So as a conclusion, to make the right choice when purchasing a GPS blocker, figure out the frequencies involved with the GPS tracking device first. Or should you have any doubt in selecting one for yourself, please feel free to contact us, and we will try our best to help recommend a suitable one of your need.

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4G LTE Networks: Opportunities, Further Perspective and Possible Threats

The history of the fourth generation network(LTE) began on December 14, 2009, when two Swiss telecommunications companies Telia-Sonera(one of the leaders in the cellular market in Sweden and Finland) and Ericsson(a manufacturer of telecommunications equipment) announced the launch of the first official commercial network of 4G standard(LTE) in Stockholm and Oslo. Another significant event for the 4G network was the recognition of its new fourth-generation wireless standard, the International Telecommunication Union at the end of 2010. In the UK and many other European countries, 4G networks have also been actively developing.

The main objectives of the LTE network are:
1. The increase in speed capabilities of mobile data transmission systems.
2. An increase in the range of services due to fast data.
3. Reducing the cost of mobile data.

Currently, some of the largest telecommunication companies, such as: Networks, Alcatel-Lucent, Siemens, Nokia, etc., are developing LTE networks. The claimed characteristics of the new generation network are impressive, the data transfer rate can reach 326Mbit/s when receiving and 172Mbit/s when transmitting. The declared radius of the work was also released when transmitting data, so, it is a tower, depending on the power and frequency used, can transmit data over distances from 5 to 100km.

The main differences between the 4G network and 3G network are:
– significantly increased speed
– more efficient use of the frequency spectrum
– reduced delay when sending data packets

LTE is already more and more like a cable connection than on a 3G network, due to its low response time(less than 50m/s) and high speed. By the way, there are other little-known 3G-based mobile communications. In the course of analysis by specialists from analytical companies of the new generation network, they calculated that when LTE is introduced into the masses, the cost of data transfer will decrease by 6 times, when compared with the 3G network, which will reduce the cost for ordinary users. Also, with an increase in data transfer speed, the range of multimedia and entertainment services offered (for example, mobile TV) will also increase, which will become a new niche for operators to earn. However, the profit from ordinary calls will also decrease, as for saving, people will use the services of free IP-telephony.

Let’s put it simply, when the data transfer speed increases, the quality of services provided by mobile operators immediately rises, which greatly contributes to the development and distribution among large masses of users, making tasks for mobile networks more feasible and affordable.

However, there are also disadvantages in the network of a new generation. The developers focused on data transfer speed, but forgot to think about security and the network did not receive decent protection. There are already many user reviews that their confidential information(transmitted data, conversations, etc.) is easy to be intercepted and used at other people’s discretion, using all possible bugs and other listening devices that support working with the new standard. And due to the high speed and excellent quality of data transfer, such intercepts will be very difficult to track. Therefore, developers and specialists advise, if you do not want your confidential information to fall into the wrong hands and not harm both you and your business, use 4G cell phone jammers that support work with new generation networks(LTE). Today, one of the best online stores that specializes in these devices is our Jammer2UK.com . We are ready to give you advice and an answer to any of your questions regarding the selection and configuration of the jamming equipment.

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Application of Mobile Phone Signal Jammers in Prisons

Imagine this, prisoners in jail trade cigarettes or even drugs with others and make big money from this due to lack of supplying sources behind bars, or they call together gangsters to bully other guy who has ‘broken their rules’. Do these remind you of very familiar scenes that you seem to have watched in movies or TV serials? The fact is that these are not just imaginations by the directors, but real things that take place in jails or prisons. In the meanwhile, the access to cell phones make it worse and even beyond control.

Technology should be used to jam mobile phone signals in prisons, an inspector at Britain’s largest jail has said.

David Jamieson, chairman of Wandsworth prison’s Independent Monitoring Board, says illegal phones fuel prison drug trading, bullying and gang problems. Behind bars, mobile phones can cost £400 each. He said that the trade had been worth £9m in 2008, when 7,000 phones were seized.

The Prison Service says signal blocking is technically challenging and not quick, simple or cheap to implement.

Mr Jamieson told the BBC’s Inside Out London programme that he believed three times as many mobile phones were in circulation within prisons as had been seized. Ever-smaller handsets allow phones to be smuggled in by prisoners, visitors or corrupt staff, he said. And some are even thrown over prison walls.

It is almost impossible to stop them coming in, Mr Jamieson said, but the signal-blocking technology would render them useless, preventing prisoners from using them to co-ordinate crime and intimidate witnesses on the outside.

Mr Jamieson said, “The technology… does exist. It would cost about £250,000 to equip a prison with mobile phone jamming devices to jam calls. That would pay for itself quite easily over time.” However, he accused the government of “pussyfooting around” this issue.

The ministry of Justice said that it was already an offence to smuggle a phone into prison and that a new bill included laws intended to make it illegal to possess one in jail.

“The objective of this clause is to act as an additional deterrent to those who consider trafficking a mobile phone and/or its component parts into a prison, or to have them in their possession and to punish those who do,” said a spokesman.

How about in the US
Jamming can be extremely effective if the signal is strong enough to cover the frequencies range telecoms use to send signals over their networks, whether they use CDMA or TDMA bands, says Anthony Ephremides, an information technology professor at the University of Maryland.

“There really is no simple or practical way to a disable a jammer. In order to destroy a jamming signal someone would have to be extremely savvy and sophisticated technologically. It’s a huge advantage for jamming,” said Ephremides.

The problem occurs when jamming equipments fall into the wrong hands. NBC News reported on the growing use in organized crime of jamming equipment to disrupt GPS systems throughout Europe and Africa to smuggle drugs and traffic weapons. Simple criminals use jamming technology to disable garage doors and alarm systems.

The long-running battle, jamming critics say, is about money. There are two forces at play: a rush of companies developing technology and equipment under a public-safety premise for the $75 billion American corrections industry, and the ability to patent and distribute new technology with government approval.

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Can a GPS Jammer Stop the Driving Recorder ?

With the popularity of all kinds of vehicles, GPS signals are being widely used throughout the world. Consequently, gradually GPS jammers are also in much more demand by people in the hope of fight against the unwanted GPS tracking or even spying. Or alternatively, GPS jammer might be utilized for evil purposes. So what is the background of GPS in the UK? Now let’s take a look.

As has been confirmed by a secret network of 20 road surveillance stations across the UK, criminals are regularly trying to block GPS signals. The Sentinel network, set up by the government’s Technology Strategy Board (TSB) and operated by Chronos Technology in the Forest of Dean, United Kingdom, has recorded an average of ten disruptions per month since September 2011.

“Our jammers use very small GPS receivers like those in cell phones. They are installed in places where our partner companies have unexplained failures in their professional GPS jammers,” said Chronos CEO Charles Curry. “The jammers sweep a signal through the GPS band by 1.5 gigahertz and we record the influence that affects the local GPS signal.” The British surveying authority Ordnance Survey was a victim of these GPS failures.

Details of the 60 incidents so far are rather sparse, as Sentinel is still evaluating the causes, but at least one jammer has been confiscated. Curry says, most of the jammers appear to be used by truckers to prevent tachographs from working in the cab, prevent their superiors from being tracked, or prevent thieves from stealing commercial vehicles. “The one which was seized by police is the type that fits in a vehicle and is powered by a cigarette lighter socket,” he says.

It is odd enough in some places that more than one person appears to be responsible for the jamming: Chronos tries to differentiate between different jamming stations in order to “get a better idea of how many people are interfering with GPS in a certain place”. Vigilantes could be a source: A big problem with GPS is the way some small villages and towns visit dangerously oversized trucks – often stuck in tiny streets – to follow the shortcuts recommended by the satnavs. It is possible for locals to place jammers to prevent motorists’ anti-social behavior.

The GPS signal is weak and can be easily jammed – its radiation is only as intense as a car headlight from a distance of 20,000 kilometers. Hundreds of online retailers illegally sell jammers online and at the same time the GPS signal has quickly become the critical national infrastructure. In addition to positioning services via satellite, the atomic clocks on board the satellites also provide important clock signals for systems as diverse as cell towers and banking systems – they fall over without GPS.

Therefore it is not surprising that a US company called LightSquared, which once wanted to operate a 4G cellular service very close to GPS frequencies, was prevented by the Federal Communications Commission. It was unable to show that its technology could avoid GPS signals that deviate from the allocated bandwidth.

The conference will also hear how the GPS signal jammer can be faked so that navigation devices are lured in the wrong direction. Also you can see videos of how spoofing works at the University of Texas. Spoofer could become the last equivalent of destroyers who made false lights to pull ships onto the rocks. The general Lighthouse Authorities, for example, suspect that ships are now so dependent on GPS signals that they can safely expect “an incident” in the world’s densest ship – the English Channel – that will be caused by GPS interference, traffic jams or spoofing in the next decade.

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Are WiFi Signal Jammers Legal Or Not ?

Nowadays, you are likely to get free WiFi connections no matter where you find yourself: whether a shopping mall, cafes, restaurants, libraries or even some city areas. — these WiFi networks help by keeping you stay connected. Due to open access to Wi-Fi at these places, obviously many people are taking full advantage of this to stay connected even when they do not have anything to offer these places until somebody does something to save these places. The solution we are talking about here is the Wifi jammer!

Jamming devices, according to the FCC, are defined as illegal radio frequency transmitters, which are designed to interfere with, block or jam authorized radio communications such cellular, gps and wifi/bluetooth frequencies, etc. Why jamming technology may be termed illegal? One reason is that it is currently unable to differentiate between desirable and undesirable network communications. For example, a WiFi jammer can disrupt all radio communications available on any device that makes use of radio frequencies for its operation. These devices are affected only if they are in the radius of operation of the jammer. A WiFi signal blocker does this by emitting radio frequency bands which go against that of the targeted device, thus preventing the device from maintaining or even establishing a connection.

Jammer devices also include WiFi jammers and mobile phone jammers which can prevent your cell phone from receiving or making calls, emails, and text messages. Moreover, they can prevent your your WiFi enabled device from getting connected to the internet for several operations, keep you from receiving the exact positioning signals with the use of GPS, and prevent you from getting located by a first responder in an emergency.

Are WiFi jammers legal or not?

The federal law prohibits the use, operation, sale and marketing of any type of jamming device. The prohibited devices include those that interfere with mobile and GPS(Global Positioning Systems), PCS(Personal Communication Services), WiFi(wireless networking services), and police radar. The law is designed to prevent the use of these devices because they know that they pose serious safety risks and may lead to severe accidents. So the use of cell phone jammer is a violation of the federal law,and very soon those who are violating this law will be cracked down by the law enforcement agencies and the enforcement bureau. Since they pose serious risks to the important public safety communications and they can prevent people from calling 9-1-1 and other emergency numbers. –That explains why it is now unlawful to sell, distribute, advertise, or market the jamming equipment to people and consumers in the United States. And finally, the jamming devices can alter the law enforcement communications. Therefore they are doing this through outreach, education, and aggressive enforcement to tackle this problem. In the US, the only legal buyers of such equipment are government employees.

However, the legislation regarding jamming equipment varies from country to country. In the UK and Japan, anyone can own a jammer– as long as they don’t use it.

Also dozens of countries, including Canada, Mexico, New Zealand, Norway, Turkey and others, allow the police or prison officials to use jammers. It is said that Mexico for example allow use of cell phone jammers in public areas such as churches and hospitals.

In Chinese and Indian, schools use jammers to stop cheaters. And Pakistan allows jamming in banks and libraries.

It is worth mentioning that most countries, including the U.S., use jammers to thwart cell-phone-triggered bomb attacks against government leaders. The U.S. military once used jammers to stop roadside bomb attacks in Iraq.

As a conclusion, we should repeat the fact that you definitely need to do the best and check your local laws and before buying a signal jamming device make sure to check the frequencies you need to jam. We are trying to protect you here, so keep in mind that the number one thing that you should do here is to check the laws of your nation and right after proceed to purchase.

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How Can a Signal Blocker Jam Your Cell Phone ?

What is a cell phone signal blocker? How does it work ? Today we are going to illustrate on these.

If we think of a cell phone as a handheld two-way radio, since radios can be interfered with, so can cell phone signals. In this sense, cell phone signals can be blocked/jammed, just like any radio.

Definition: What does a Cell Phone Jammer mean ?
A cell phone jammer is a piece of equipment capable of blocking reception or transmission of cell phone signals. – This is mostly done by creating some form of interference at the operating frequency ranges of cell phones, which results in no signal or significant loss of signal quality.

Cell phone jammers work on the same principles as that of jammers used in preventing radio communication. They either function by disrupting the cell-phone-to-base-station frequencies or base-station-to-cell-phone frequencies. A mobile phone communicates with its service network through a cellular base station(cell tower). As the cell phone user drives down the street, the signal switches from one cell tower to another.

Specifically speaking, signal jamming devices basically emit the same radio frequency bands as cell phones do. In this way, the cell phones involved cannot tell which is from the regular base station, thus “interference” is achieved. As long as there is a device transmitting the same frequencies as the cell phone, it makes a lot of “noise” when the cell tower is trying to connect to the phone. Consequently you will find that the signal is unrecognized by the phone, and making or receiving a phone call is basically impossible.

In the early days after invention, cell phone jammers were able to block only one set of frequencies, such as 2G(GSM), while nowadays more complex mobile phone jammers have come into being, which could block several types of networks in one go, such as 2G 3G 4G, or even WiFi/GPS signals.

Although cell phone jammers could be used practically anywhere, they are mainly used in areas where silence is expected or required. When a cell phone jammer is active, most cell phones show no network signal, and when the cell phone jammer is switched off, then the cell phone becomes active again. Cell phones use unique frequencies for talking and listening, and most cell phone jammers block either of the two frequencies, indirectly providing the effect of prevention of both.

In modern society, normally mobile phone jammers are used by law enforcement and military to limit and disrupt communications during various situations. Certain organizations use cell phone jammers to prevent corporate espionage by blocking communication within sensitive areas. Portable cell phone jammers are also used by some people to prevent others from using cell phones in their immediate vicinity.

In all, cell phone jammer undoubtedly bring us great help when communications at certain occasions are unwanted. Should you have any doubts in selecting an appropriate cell phone jammer for yourself, please feel free to send us a message.

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Protect Your Privacy With Signal Jammers

Lots of people are complaining every day that their privacy is broken and nothing they do can be hidden from other people and various spying organizations, such as NSA or other government departments. We at jammer2uk store therefore decided to provide you with a couple of advices regarding how to protect your own privacy with the help of various jamming devices, without harming/influencing other people.

First of all, it should be noted that signal blocker/jammer is a weapon, and it may do bad things in wrong hands, for example criminals may utilize signal blockers for committing a crime. So please be careful with those.

To start with, we will introduce the most dangerous device that can be used for tracking, eavesdropping, which gathers tons of your specific data such as login/passwords, emails and your contacts from your smart phone. – No matter who is the manufacturer and which mobile OS it is running on. It’s a fact to most people that one device has all the data on you – that is why we say modern smartphones are potentially very “dangerous” though they bring you great convenience at the same time. Such data includes your personal information, your current coordinates, your friends, even your company’s business data and so on.

All of these are the main reason that hackers are always trying to find new ways of getting into your smartphone, and if Spiegel’s reports are true- secret services such as NSA are spying on your smartphone too, which is the most simple and the cheapest way to obtain lots of data on you in a really fast manner. Among all, the most dangerous here is the fact that you cannot do anything about it, isn’t it? And even worse thing is that there is no such antivirus, or firewall, or encryption method that will be able to protect your data without killing the functionality of your gadget.

Furthermore, all the encryption procedures are so complicated that most of the people won’t simply mess with that. Under this condition, we provide two decent options available for concealing your information. The first option is to use the GSM and mobile internet jammer, which will help block the related frequencies and thus hide you for a short period. However, the drawback is that you won’t be able to make or receive a phone call. Then the second option is to avoid storing private and valuable data on your portable devices, smartphone or tablet. Both of those are going to cut the functionality of your device, but will surely prevent data leaks.

Secondly, wireless networks, which most of the people find it difficult to break themselves away from, are the other thing you should worry about or pay special attention to. They are not as reliable as you may think, and hackers are using this point. In fact, nowadays most of the smartphone users are connecting free Wi-Fi hotspots in public places and use them not only to surf the web, but also to install updates and processing their mobile banking information. All those doings are rather dangerous, especially for Android users since Android OS is using a weak version of SSL encryption with RC4 algorithm, instead of SHA1.

Still many people are putting their private information at high risks willingly: they connect to free WiFi hotspots at public places, they share it through social networks with their smartphones, and transmit it over the Internet with an unencrypted protocols, and the like. – That is why we always tell our readers that the safety of their private information should be their concern of top priority, and no one will be able to protect it if they themselves won’t do at least something for it.

So from now on, protect your private information, though it is easy, it may even save your life someday!

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Your Car Is Spying On You and Collecting Your Private Info

Car is obviously one of the most widely used means of transportation, the history of which is a very glorious one. Along this process, the invention of the wheel was certainly a step in the right direction. However, when the automobile was first invented at the turn of the century, no one even knew the capabilities that the traveling device would grow to have. It turns out that is has grown to become not only one of the most trusted means of transport, but also a man’s best friend. Nowadays the car is a status symbol, acting as a gauge of the livelihood of the person who drives it. What people didn’t realize is the fact that it would become the object of a lot of controversy regarding privacy one day.

As an important step in the development of security and tracking, the invention of the GPS undoubtedly is a key factor for pushing forward the advance of society. Cars equipped with GPS devices might be doing a little more – they are sleek and smart, and many people prefer and feel safer in them, and even totally rely on them. But the GPS device might just be a little smarter than most of us may think, which seem to be indicated by recent revelations. In the light of car technology experts, the fact that one knows exactly where the person is driving at any one time might have enormous potential. Manipulating that information, one can be able to acquire and sell personal information at a price. I believe that the sale of personal information is nothing new to us, and even has the potential to make someone big money. Cars are tracking people in much the same way as smartphones do today. And instances of using smart phones to obtain personal information are not new either.

That targeted advertising services and marketing make it more lucrative explains why there is increased political goodwill in trying to curb this growing trend. Chuck Schumer, once senator of New York, has led the demand for federal regulations to control any potential breaches. According to the senator, GPS devices, black boxes and vehicle-to-vehicle devices collect a lot of information that can be collected and sold by vehicle manufacturers. He called on the relevant organizations, the national highway traffic safety administration and the federal trade commission to establish clear guidelines on type of data that these devices can collect. His suggestions also go as far as giving drivers the option of opting out of such programs that collect their personal information.

Undeniably, there is some truth in these allegations of car spying and collecting information. As long as the car tracks everywhere the individual goes, then it knows the person’s private information regarding where they drive to and from every day, where they travel and how much they spend on their trips etc. It tracks and records all the movement so it knows where the person unwinds during their free time, where they eat and who they visit, and so on. Moreover, car tracking even knows the favorite holiday destinations that people have. Pam Dixon, executive director of the World Privacy Forum, told the Washington Post: ‘Most people don’t realize how deeply ingrained their habits are and how where we park our car on a regular basis can tell someone many things about us.’

But do or will the car companies share this information? The fact is that many of these firms keep tight-lipped about how and when they use this data. A study done by the government accountability office reveals that up to 90% of the manufacturers of cars, security and tracking devices share the information they collect.

Judging from all of the above, apparently it will be wise to use a universal GPS jammer because the car spying is and will be an ongoing concern, and the fact that it takes advantage of devices that people trust to keep them safe makes it even worse!

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Why You Need a WiFi/Bluetooth Jammer ?

The development of mobile devices has greatly promoted the coverage and popularization of WiFi network. Nowadays WiFi and Bluetooth frequency bands, which mainly use 2.4GHz frequency range, are very commonly used for most people to get access to the wireless internet.

However, despite their unquestionable usefulness WiFi and Bluetooth frequencies may be used by the government for shady activities (for example, indoor tracking that is spreading with the lightning speed), which might violate the privacy rights you definitely have. In this case, WiFi is actively used to track your location indoors, mostly through the hotspot location triangulation in a way similar to the cell phone tower location triangulation. And Bluetooth is also used for indoor tracking, particularly in Bluetooth beacons tracking technology. As a precaution against the above situations, WiFi/Bluetooth jammers can help to protect your privacy and hide your location indoors.

The next threat you should be aware of is related to the wireless internet usage. It is the fact that the massive flaw discovered in WPA2, the encryption standard that secures all modern WiFi networks, launched the possibility that anyone near you could easily access your information if you use a WiFi network. Both WiFi and Bluetooth are poorly protected against hackers thus your personal or business data is in highly potential danger all the time if there is a wireless access to the internet nearby. Not only information about you can be stolen, also there are far worse things that might happen: law enforcement agencies can connect to your webcam and watch everything through it, or they can simply use hidden cameras and microphones installed in your house, for eavesdropping and snooping on you secretly, getting back streaming data with the help of WiFi and Bluetooth connections. In such cases, you will need a powerful wireless signal jammer, bluetooth jammer or WIFI blocker. All these devices work on 2.4GHz signal so actually you will only need one device – 2.4GHz WiFi jammer.

Furthermore, smart house systems become more and more in demand nowadays. And devices connected to internet which are so-called “Internet of Things” are spreading everywhere. With such state of things all connected housewares thus may become eyes and ears in your own house, serving to expose your privacy to the government. Under this condition, only portable or desktop WiFi jammers from this category will be able to solve the problem in your advance.

In other cases, there are also some drones and UAVs(Unmanned Aerial Vehicles) controlled via 2.4G frequency which might also be used to spy on you, though most part of those robots are operated with the help of remote controls. So as to be absolutely sure that no spy drone will be used for surveillance on your private meetings, business operations or any other events of your life, you need to resort to a remote control jammer as well as a wifi jammer.

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How to Choose a Correct Cell Phone Jammer

More often than not, some of our customers choose the wrong cell phone jammer when placing an order. So when we doubt that the customer may have ordered the wrong item, we sent them an email to verify and ask them to confirm what frequencies they want to block. Some customers say that they are not too savvy on this aspect. Or others even say that they order the cell phone jammer judging from their appearance such as compactness or other features.

Truth be told, choosing a correct cell phone jammer is really not so difficult as you may think. Or we don’t need to be that professional or savvy in this field to get a good jammer which satisfy our demands.

Before you place an order on a jammer, you should take a look at its specifications which usually show the frequencies list it can jam. For example, if a cell phone jammer can block GSM/CDMA 3G frequencies, this means normal phone calls can be blocked. If in the specifications it lists GSM/CDMA 3G 4G frequencies, then this jammer will help to block normal phone calls, and 4G frequencies which are mainly for cellular network(for mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television, etc.)

Or conversely, you can know whether a cell phone jammer is the correct choice based on what purpose you want to achieve. When you need to simply block the annoying or endless phone calls made by someone in public places, you can just order a mobile phone jammer which blocks GSM 3G signals. Or when you want to block not only phone calls, but also cellular network and WLAN frequency of cellphones to get rid of those ignorant bastards who finish-up sitting near to your table at restaurants etc, then you need to look for a cell phone jammer which can block GSM 3G 4G WiFi frequencies in one go.

In this way, the jammer selection become very simple. And a final thing remains is to choose a portable or desktop jammer. This is of course nothing difficult — you can decide to buy a handheld or desktop cell phone jammer based on the occasion you will carry it into use and the jamming range you want to achieve.