All About Scanners
What are Scanners Anyway?
A scanner is a radio receiver (it cannot transmit) which allows you to scan multiple frequencies at one time for two-way radio activity. These devices are commonly known as "police scanners" in that most people use the devices to listen to police radio communications although fire department monitoring is almost of equal interest and scanners can also be used to monitor the two-way radios of taxis, mall security, commercial aircraft, ambulances and so much more. Just like an FM radio station might broadcast on 105.7 FM, a police department will use, for example, 155.625 FM for its dispatcher to communicate with the patrol cars. Because a police department, unlike an FM radio station, does not need to broadcast continually with talk or music, but only when there's an incident to discuss or respond to, a scanner allows you to sample a multitude of local (within 20 miles or so) public safety agency and business radio channels for activity. The scanner will stop on the first channel it comes to that has activity and the radio will resume scanning when that radio transmission has ended. Note that there are many new types of radio systems such as digital and trunking which are discussed below.
* All about Base/Mobile Scanners
* All about Portable Scanners
* All about Pre-Programmed Scanners
* All about Trunking Scanner
* All about Digital Scanners
* All about Communications Receivers
A Short Scanner History
Back in the early days of radio, in the early to mid 1900s, tunable radio receivers were used to monitor police channels. In actuality many police departments used a frequency just at the end of the AM radio dial around 1700 KHz to broadcast to their patrol cars. In the 1960s, when police and fire departments were using FM radio channels around 40 and 155 MHz (VHF Low and High band), enterprising radio enthusiasts developed the scanner which in effect performed a rapid tuning function, searching local radio channels for activity by "scanning" them. The first scanners scanned four or eight channels. To monitor these channels people had to buy crystals for the specific radio frequency used by their local departments, and install them inside the scanner. In later years a keyboard replaced the crystal and now you can program thousands of channels into a scanner from a keyboard or a PC.
Who Uses Scanners and Why?
Scanners are used by a wide spectrum of people, from radio hobbyists to everyday folks who just want to keep an ear on what's happening around town. Scanners are also used by the news media as well as people who love news and want to hear all about it as it happens. Others are concerned in today's environment for personal and neighborhood safety and want to stay in tune with the fantastic job our public servants perform. Speaking of our public servants, police departments nationally use scanners to allow them to keep tabs on adjoining departments and jurisdictions in case incidents in one community, such as a car chase, may move into their own or, in the case of fire departments, they may be called for mutual aid at a fire. This is called communications interoperability and scanners can be a critically important tool for public safety in this manner. Newspapers, TV and radio stations all use scanners to gather the news and report on it. There are actually hundreds of ways scanners are used for a variety of public safety, social and even entertainment purposes. Visit this page to read many real life stories of people in every day situations that describe why they decided to buy a scanner and the many ways they are used.
Buying Scanners for Security, Information or Enjoyment
Scanners keep you in the know better than the local news, provide a sense of security, and all the while scanners can be a lot of fun. When buying a scanner for your home, work or as a gift, there are a number of key points to remember:
Determine the type of radio system your local town and county uses
Most communities still use basic radio systems that can be scanned¯ using low-end/inexpensive scanners. A low-end scanner though will not have the features, such as alpha-tagging (allowing the scanner to display Chicago Fire rather than a frequency) or a PC port, that can be very useful. Your community or region may also use advanced radio systems which will require a more expensive scanner. To learn if the communications in your region require you buy an advanced scanner visit our Compare Scanners page.
Scanners can seem complicated at first, but the low-end models, in particular, are very easy to use. When buying for personal use or as a gift, try to keep it simple by programming and listening to the police and fire department for your own community and perhaps some surrounding communities. Then, as you get more familiar with scanning you can broaden your listening if you desire.
Programming Your Scanner
You must program the local police and fire department frequencies of course before you begin listening. This is akin to entering your favorite AM-FM radio station, but there are a lot more public safety frequencies to choose from. There are a few ways to go about programming your scanner. First, you can buy one of our frequency guides to program the radios yourself. After reading the scanner owner's manual to understand the programming process, you look up the frequencies and the trunking system details in our book and then enter the information into the radio. Some web sites also maintain this data. The frequency guides offer a wealth of information on all sorts of public and private entities that use radio including police, fire, EMS, DOT, DPW, fire towers, railroads, utilities, colleges, malls, auto racing and so much more. If learning the programming process and finding the frequencies doesn't appeal to you, you can have Scanner Master program your scanner.
Frequently Asked Questions (FAQs)
How far will I be able to listen?
Distance depends on too many factors to provide an easy answer, such as the elevation of your home, whether there are hills or other obstructions between you and the agency you wish to monitor; the transmitter power of the agency you wish to listen to, etc. These and other factors all play a part. Generally speaking, with a handheld or desktop scanner you can hear in a 10 to 20 mile radius, but that's not set in stone.
What is Trunking?
As public safety agencies and businesses grow they require more and more radio frequencies for their operations, consequently available radio spectrum has become more valuable and more difficult to find. To help resolve this problem, radio manufacturers developed trunking which works on the same principle as a trunk telephone line. Let's take for an example the city of Worcester, Massachusetts. This mid-size city used to have two or three frequencies for the police department and two or three for the fire department as well as one for public works and one for parks. Now, with their trunking radio system, they have upwards of 50 or 100 groups of users on 10 radio frequencies. Here's a listing of just some of their talkgroups¯:
04-041 Fire Ops A North
04-042 Fire Ops B South
04-044 Fire Dispatch
04-045 Fire Administration
08-041 Police East Patrol
08-042 Police West Patrol
08-044 Police Traffic Enforcement
09-006 Police Auto Theft
12-041 Water Department
12-042 Water Filtration
12-043 Sewer Department
12-044 Health Code/Sanitation
12-045 Street Department
12-056 Snow Emerg./Plowing
12-083 Traffic Signs & Signals
One of the frequencies in the system is the control¯ or data¯ channel, continuously broadcasting a stream of computer data that sounds like a buzzsaw over the air. Every time a police officer, a firefighter or a sanitation worker presses his microphone button an instantaneous computer command is sent out to all the other users within that person's radio group to move to one of the nine available voice frequencies in the system. The channel the group is assigned is almost completely random so there's no way to follow a communication unless you have a trunking scanner that works on a principle similar to that of the actual two-way radio. Hence, the TrunkTracker. One moment an officer in the police east side traffic division may be calling his dispatcher on one of the nine frequencies, and seconds later that dispatcher may reply to that officer on a completely different frequency. So now, a small group of radio users, such as the Water Filtration division, can effectively have their own radio channel. It's not a frequency per se, just any one of the 9 available radio frequencies as long as it's not in use by another talk-group of users.
The two major types of trunking systems are manufactured by Motorola and by M/A-COM (known as EDACS). A popular business trunking technology is known as LTR. Most, but not all, public safety trunking systems operate on the 800 MHz band. As the technology has evolved over time, each manufacturer has some different flavors of their trunking system. With Motorola youā€™ll hear about Type I, Type II and IIi. Type I requires something called a fleet map to work properly (although these systems are gradually being phased out). EDACS has narrowband, wideband and SCAT. There are a number of LTR style systems, including one known as MultiNet for public safety (there is no scanner today that can track it) and Passport which is primarily for business communications. There is also some encryption on these systems which makes it impossible to monitor. All of it sounds very complicated and it can be, but here we specialize in providing you with the information to make it easier to set up trunking for your area and once itā€™s done right it may never have to be touched again. Note: EDACS, MultiNet and Passport are trademarks of their manufacturers.
Trunking systems can be complicated to program for novices (although our BuTel software makes programming much easier), but you'll find that scanning these trunked systems to be more pleasurable, interesting and informative than ever before. You can hear both sides of a conversation and you can listen in to just those groups which interest you.
Scanner Basics/Information and FAQ's
What is Digital and APCO-25 all about?
Just like your cell phone, a digital two-way radio system converts voice into ones and zeros and transmits this data to another radio which decodes the information so the voice communication (sometime sounding a bit robotic) is heard on the other end. Older public safety radio systems are often being replaced with the new digital systems. There is no way to upgrade an older or non-digital scanner. You must buy a digital scanner (such as the Bearcat 296 or 796) or a digital-ready scanner (the Bearcat 250 or 785 which accept a digital card) in order to monitor digital communications.
Digital scanners decode APCO-25 non-encrypted transmissions automatically (encrypted communications cannot be decrypted). A few agencies operate in encryption full time. There are also a few non-standard digital radio systems that are not monitorable at this time such as EDACS ProVoice, M/A-COM OpenSky and European Tetra. Many agencies also used MDT's (mobile data terminals), the computers in the patrol cars as well as cellular and NEXTEL phones for private communications. These cannot be monitored in any way.
What are PL and DPL (private line & digital private line) or CTCSS and DCS sub-audible tone codes?
Many scanners have the ability to program both a frequency and a sub-audible tone code (PL/DPL). It's not required that you use it but it is recommended if you have the PL/DPL information. As many agencies and businesses share radio frequencies they use these codes to insure that they only hear others within their department or company. You can do the same. PL helps limit interference by pre-selecting only those transmissions your most interested in and filtering out unwanted conversations. PL data is not always available but most scanners today provide a method of automatically determining the PL or DPL in use.
Can I listen to cellular phone calls? Can scanners be modified to listen to it?
By federal law monitoring private phone conversations is prohibited. No scanners made in the last 10 years have been capable of monitoring cell phones or are capable of being modified to do so. Most cellular phones are now TDMA or CDMA digital which is completely different from APCO-25 digital and couldnā€™t be monitored even if the cellular frequency range was still included in the radio. Government agencies can purchase scanners which still contain the cellular band but special ID is required.
What is this new Close Call feature of some of the Uniden scanners?
Close Call allows the scanner to instantly tune to most any standard (non-cellular/Nextel) radio transmission within your line-of-sight, or in some cases even further. So, if you're at a mall, a sporting event, or happen by an accident scene for example and you don't know the local security, event or police/fire/EMS channels, Close Call will automatically tune your scanner to the frequencies being used. If you've been waiting for the right time to buy a new scanner, buying a scanner with Close Call is a great reason to finally make the move.
How can software help me with scanning?
Other than some of the low-end scanners, most scanners today are computer programmable. Using a serial cable and software you connect your scanner to your PC and then you can create multiple files for different areas or events to which you might take your radio. For trunking scanners and/or scanners with alpha-tag capability, programming on a computer (usually in spreadsheet like form) is considerably easier than programming on the scanner itself. More advanced software allows you to also control your scanner from the PC and log activity, record audio, and do much more than you could ever do on your scanner alone. Uniden includes demo software with their scanners but Scanner Master recommends the BuTel ARC (Advanced Radio Control) software which is widely considered the world's best. It's extremely easy to use, loads and works seamlessly with your PC, and itā€™s very powerful and feature rich.
What accessories do you recommend?
Antennas - There is no better way to improve reception, whether for base or mobile scanning, then by adding an outside antenna. For home or office scanners we recommend a base station antenna, such as the Discone for all-band monitoring. If you want to really improve performance on a single radio band, check out our professional base station antennas, either omnidirectional or directional for most receiver gain. Aiming a yagi (beam) antenna at a station or region that uses a common band (such as 800 MHz trunking or 460 MHz UHF) will pull in signals you never dreamed of. For mobile scanners we urge you to mount a mobile antenna somewhere on your vehicle. Getting the antenna out from under the steel roof of your car or truck will provide a huge improvement. Not everyone wants another antenna on their car so we offer various types and mounting options. For portable scanners you can buy antennas tuned to specific bands (such as 800 MHz) for improved trunking performance for example, but other bands will suffer.
Software - For all scanners with a PC connection we highly recommend scanner software which will make programming easier and operation more enjoyable. If you're not convinced go online and check out the demo software that we offer for many models.
Frequency Guides - We offer specialty frequency guides for the Northeast, Southwest and Police Call on CD only, the 7-volume set that covers the nation.
It is 100% legal in the United States to purchase, own and operate a scanner radio with a very few minor exceptions. We note that because radio law sometimes, but extremely rarely, changes, and because we are not attorneys, you should check your state, local and federal laws if you have any concerns.
There are a few states that have laws on the books regarding the use of scanners in motor vehicles. Kentucky, Indiana, New York and Florida come to mind. There are a few additional states where it's illegal to use a scanner in the furtherance of a crime. Click these links below (which may or may not be up-to-date) for further information:
It is illegal to intercept cordless phone communications (most cordless phones today are spread spectrum and cannot be monitored anyway. It's also illegal to monitor cellular phone conversations and for the last 10+ years the major scanner manufacturers, by federal law, have not produced a scanner capable of monitoring the cell phone band. At any rate, because 99.9% of all cell phone calls now are CDMA, GSM and other highly advanced types of digital (not APCO-25 digital), cell phone calls couldn't be intercepted anyway.
It is also illegal to decrypt encrypted communications. Most public safety communications that use DVP/DES and other types of highly-sophisticated encryption couldn't be decrypted without years of work and a supercomputer anyway. Luckily, relatively few public safety agencies in the U.S. use such systems. In other parts of the world, particularly we know in Europe, the public safety radio systems cannot be monitored.
Scanners are a well regarded and respected tool for the news media, public safety agencies themselves, and for the general public. Americans like to be in the know. They like to be aware of what's going on around them and they like to help the police and fire services whenever possible, by reporting crime, fire, and the like. Knowing what the local authorities are doing and perhaps helping (without interfering -- very important) after having heard something on-the-air, benefits us all.
So scanners are completely legal to own in your home, on your person, and, in almost all states, in your vehicle. They help you build a healthy respect for the job our public servants our doing while at the same time keeping you in the know. Buy a scanner radio today and be informed and enjoy!
How Scanners Deliver News as it Happens as well as Entertainment and Peace of Mind
This is a long way of asking, "Why are scanners so great?" Or, "Why are scanners such a useful and enjoyable product for everyone? There are many reasons why and below we've just begun to cover them.
Let's take the first part, "How do scanners deliver the news as it happens" We all want to know what's going on around our city, our nation and the world, but it's the local news that's most important to us. It's what's happening in our community, in our neighborhood, that we most want to follow.
We can watch TV, read a newspaper or look online for our news. But in all cases it takes time for a reporter/photographer to go to the scene of a fire or a bank robbery and report. With cutbacks in news organizations of late, most public safety incidents won't be reported on at all, or the report will be delayed. And, if you're just curious why that police car raced down your street, you're likely never to know by just relying on news services.
With a scanner you solve all these problems. With a scanner you hear the dispatch* and then can generally follow the police and fire communications as they report from the scene.
So with a scanner you learn of the news "as it happens" rather than relying on some news service to, perhaps, go to the scene and file a report. The media relies on scanners, too, so by using a scanner you'll know right when your local TV and radio station knows when something important is happening.
With a scanner you'll also be entertained. Let's face it, listening to police chases live is unbelievably exciting. Hearing firefighters call for more water pressure as they're inside a building fighting a fire is thrilling. Hearing planes and trains be dispatched and routed is just plain fun. And in all cases you're admiration for the jobs these public servants and private professionals are performing only grows while your knowledge and understanding of their work increases.
You can have a scanner on in the background while you watch TV. Some people even go to bed listening to a scanner at night and, over time, instinctively know and wake up when something exciting or important is happening - you can tell by the tension in the voice of the dispatchers and officers in the street who are communicating.
Particularly for kids, when you're listening to a scanner you're practically riding along in that patrol car or you're in that fire truck racing to a scene of a fire. It's really mesmerizing, entertaining, informative and educational all at the same time.
And, particularly for adults, perhaps those who are concerned about crime in their neighborhood or dry brush around their homes during the fire season, a scanner will keep you abreast of what conditions are in your area. Are police responding to suspicious persons on nearby streets? Do you hear the fire department being called out to hose down homes in the development a few blocks away? This is invaluable information that you can find nowhere else or not nearly as quickly. A scanner radio does it all.
So we hope you'll consider buying yourself or a loved one a scanner today. For information, for entertainment, for peace-of-mind, and more. There's nothing like a scanner.
(*In minor police incidents some department dispatches are sent via computer to in-car "mobile data terminals." However if the incident is at all significant all departments will use radio communications to disseminate information the quickest way its entire force.)
Copyright 2009 Richard Barnett, Scanner Master Corp
Be sure to visit radioreference.com for the ultimate resource of scanner frequencies, trunking information, radio forums and more.
A guide to The Best "Police" Radio Scanners
by N4UJW Hamuniverse.com (A Ham Radio Web Site)
See this great article on the Ham Universe Website.
Rail scanning is fun, exciting and challenging all at the same time. Read this great article about railroad radio scanning by Rich Carlson.
How can I learn more about new Scanner Master products?
If you're not already on our mailing list go to our home page and sign-up for our e-mail newsletter which will keep you posted on new products and services with monthly or bi-monthly e-mailings that you can opt out of at anytime.