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
