Police Scanner Range & Reception Issues - Pt.2

This post is part two of a two-part series and covers factors that affect the range and reception of your radio scanner. Range and reception is basically how far you can pick up any given signal and how clear those signals come in.

In part one, I covered range and reception issues such as Line of Sight, Frequency Behavior, Atmospheric Conditions, Skips and Propagation, and Surrounding Terrain.

In this second part of range and reception issues, I will cover the remaining factors that affect your scanner's range and reception including; Type of Antenna Used, Indoor Reception, Electrical Noise, Birdies, Battery Power, Station Transmitter Power, and Repeated or Non-Repeated Stations. Let's get started.

Type of Antenna  –  the type of antenna you are using plays a big part. If you are using a standard rubber ducky antenna (standard on handhelds), you will not be able to pick up distant signals then if you where using a telescoping or outdoor antenna.

When you purchase a base/mobile scanner, it comes with a telescoping antenna (mobile scanners come with a mobile antenna). These work well, however, to maximize your receiption, an external antenna is highly recommented. Learn more about the different types of antennas that are available on the market on our "Police Scanner Accessories".

Indoor Reception – indoor reception will depend on what type of structure you are in, wood, steel, or concrete. Generally, reception of lower frequencies inside of a steel structure will be weak. Receptions of higher frequencies within a steel structure are not generally affected. Reception within a wood or concrete structure varies, but is generally fair. If you are listening from home, connecting an external antenna will boost your reception and extend the range of reception.

Electrical Noise – electrical devices can generate radio signals that can be picked up by your scanner resulting in interference with existing frequencies. Causes include electrical machinery, vehicle ignitions, motors, power lines, florescent lights, etc. Interference from electrical noise usually occurs with lower frequencies.

Birdies – birdies are signals that are internally generated by a scanner that can cause interference with some frequencies. If you have a problem with a birdie frequency, simply lock it out. See this blog post of a list of commonly known birdie frequencies.

Battery Power – the bottom line here is that fully charged or fresh new batteries will give you better range and reception than if you are running on weak ones. Most scanners on the market now include a "Battery Low" indicator to let you know when your batteries are running low. If your scanner does not have this feature, you can usually tell your batteries are getting low because reception starts to break.

Station Transmitter Power  –  base station transmitting power is measured in wattage. The more watts a transmitting station puts out, the further the signal can be received. You can learn more at the FCC.gov website.

Repeated or Non-Repeated Stations – if a radio is being used in simplex, or “talk-around” mode, then that means that each radio is communicating directly to the other radios on that frequency in that area. Simplex range can vary from several blocks to several miles depending on how much power the radios are putting out, the type and position of your antenna, and the surrounding terrain. This range is typically 3-5 miles. For ranges beyond this limitation, a repeater system is used.

A repeater is a device that is used to extend the range of mobile and portable radios. Public safety agencies need to communicate using portable or mobile radios over the distance limitations posed by handheld and mobile radios, which is approximately 3-5 miles. A repeater also allows communications where buildings usually block the radio signals.

Generally, a repeater is placed on a building, radio tower, mountain, or other tall structure. The higher up the repeater's antenna, the larger coverage area, or range the signal will have. The repeater works by listening to what the radios are transmitting and simultaneously broadcast it back over a larger area.

Hope this information was helpful.

That's it for now. Till next time stay safe and happy scanning!

-RF
Webmaster, Police-Scanner.info

Police Scanner Range & Reception Issues - Pt.1

This article is a two-part series and covers factors that affect the range and reception of your radio scanner. Range and reception is basically how far you can pick up any given signal and how clear those signals come in.

These factors include: Line of Sight, Frequency Behavior, Atmospheric Conditions, Skips  and Propagation, Surrounding Terrain, Antenna limitations, Indoor Reception, Electrical  Noise, Birdies, Battery Power, Power of the Transmitting Station, and if the station is Repeated or Non-Repeated.

In this first part of range and reception issues, I will cover several of the factors  above in the order listed, with the remaining factors to be covered in the next post. Let's get started.

Line of Sight - line of sight means you usually cannot hear transmissions beyond the  horizon, or approximately 30-35 miles away. This is mainly due to frequency behavior.

Frequency Behavior - lower frequencies behave different than higher frequencies. Lower  Frequencies travel farther giving you greater range. On the flip side, higher frequencies  travel shorter distances reducing your range. Basically, you can hear signals in the 30MHz  bands much farther than frequencies in the 800MHz band.

Atmospheric Conditions – atmospheric conditions can affect range and reception. For  example, in the summertime, reception is stronger and range extends farther than in the  wintertime.

Skips/Propagation – unusual occurrences where signals from hundreds, even thousands of  miles away are received. A skip, also called “sky wave propagation”, occurs when radio  waves bounce off the ionosphere and return to earth. Skips are most common in the summer  months and usually affect the VHF-Low band under 40 MHz or so.

Surrounding Terrain - the surrounding terrain can affect reception in different ways.  If you are on flat land or water, reception will be at its greatest. If you are in a  mountain or canyon area, your scanner will have trouble receiving radio signals or may not  be able to receive signals at all with the standard (rubber-ducky) antenna.

Antenna Limitations - the type of antenna you are using plays a big part. If you are using a standard rubber ducky antenna (standard on handhelds), you will not be able to pick up distant signals then if you where using a telescoping or outdoor antenna.

When you purchase a base/mobile scanner, it comes with a telescoping antenna (mobile scanners come with a mobile antenna). These work well, however, to maximize your receiption, an external antenna is highly recommented.

Learn more about the different types of antennas that are available on the market on our "Police Scanners & Accessories" page.

Indoor Reception – indoor reception will depend on what type of structure you are in, wood, steel, or concrete. Generally, reception of lower frequencies inside of a steel structure will be weak. Receptions of higher frequencies within a steel structure are not generally affected.

Reception within a wood or concrete structure varies, but is generally fair. If you are listening from home, connecting an external antenna will boost your reception and extend the range of reception.

In the next post, we will cover the remaining factors that affect range and  reception including Type of Antenna Used, Indoor Reception, Electrical Noise, Birdies,  Battery Power, Station Transmitter Power, and Repeated or Non-Repeated Stations.

That's it for now. Till next time, stay safe and happy scanning!

-RF
Webmaster, Police-Scanner.info

Incident Audio - Paramedic Falls from Overpass

Last Thursday (2/9), I featured an article on our Facebook page about Alexandria Fire Department Paramedic Joshua Weissman (33), who fell from a bridge overpass while at the scene of a car fire and was critically injured.

Unfortunately, Weissman has died from head injuries sustained in the fall. 

Although the accident is still under investigation, it is believed that Weissman was climbing over a cement barrier to get to the vehicle when he fell through the gap and into Four Mile Run Creek, approximately 30 feet below the interstate hitting his head on rocks in the shallow creek. 

In addition, a link to the audio recording of the dispatch and rescue operations of fellow firefighters working to save Weissman during this incident is included below. I have also put together an interactive Google map of the incident scene location for reference while listening to the audio recording of the incident.
 
You can read about the incident at the following link:

+ Alexandria Fire Dept Paramedic Dies After Fall From I-395 Overpass Into Four Mile Run Creek

Alexandria VA Paramedic Accident Audio 2/8/12 
(20min:52sec) Audio recording of the dispatch and rescue operations during this incident.

Google Map: Incident Location

View Alexandria, VA Paramedic Falls from Overpass in a larger map

RIP Paramedic Joshua Weissman - Thank You for Your Service & Sacrifice - Last Call 02/08/12

Funeral Arrangements for Weissman are set for this Wednesday (Feb. 15)

That's it for now. Till next time, stay safe and happy scanning!

-RF

Webmaster at Police-Scanner.info