So called police scanners and ham radios have an interesting relationship. Many scanners, but probably not all scanners, have the capability of receiving not only police frequencies but also ham radio frequencies. The reverse is also true for ham radios. Many ham radios, but not all ham radios, have the capability of receiving not only ham radio frequencies but also police and other frequencies. For the person that is relatively new to either police scanners or ham radio this can be a bit confusing. The use of hobby specific lingo probably doesn’t help. Perhaps the next paragraph will help a bit.
Amateur radios with the capability of “wide band receive” and “scan” capability usually have the capability to operate as a very good police scanner. Scan, of course, means the ability to move through a set of frequencies quickly over and over again. Imagine a military guard “scanning” the horizon for the enemy. The same is true for your scanner – whether for a police scanner or amateur radio scan function. The term “wide band” takes a bit more to describe. Imagine a long ruler or perhaps a tape measure laid out in front of you. Let’s use a long ruler as our example. Let’s say the ruler is 160 inches long. Down on the left side of the ruler the first 1.7 inches or so represent the AM commercial radio broadcast “band”. You will see why it is called a “band” very soon. There is a ham radio “band” that is the next 0.2 inches wide. This represents frequencies from about 1.8 MHz to about 2.0 MHz. From this example you can see that different radio services occupy different amount of space on the ruler. These spaces are called “bands” because when you display all the spaces on the ruler they literally look like bands. If you gave each service a different color then you would see many different bands of many different colors. Such a “band plan” for amateur radio frequencies can be found here:http://www.arrl.org/graphical-frequency-allocations
A “wide band receiver” then is simply a receiver that can receive any one of many frequencies. If you painted the ruler with all of the frequencies that a “wide band receiver” can receive you would see that, by comparison, that band would be quite wide. An amateur radio that has a “wide band receive” capability can usually receive frequencies outside of the amateur radio frequency bands. If that amateur radio also has a scan capability then it can operate as a very nice police scanner.
Many police scanners also can receive amateur radio (ham) frequencies. Two of the more common frequency bands that many police scanners can receive are the 6 meter ham radio band and the 2 meter ham radio band. Let’s go back to our tape measure. When we speak of frequencies, meters and MHz mean roughly the same thing. In this instance the 6 meter band is roughly 50 MHz and the 2 meter band is roughly 150 MHz. To get the rough equivalent of meters from MHz just divide MHz by 300. It’s not an exact calculation and the reason it works is beyond this article but in practice it does come in quite handy. To determine if a particular police scanner can receive the two ham radio bands above (or many others) just compare the frequencies received by the scanner to the frequency ranges from the PDF document at the link above. Be aware that the scanner must also be capable of receiving the MODE used at the particular frequency specified. Mode means type of transmission like AM or FM. It will do no good if hams can only transmit FM on a specific frequency and the scanner can only receive AM on the particular frequency.
In summary, review the manual for the police scanner or amateur radio you are interested in and see what else it can receive that you may not have been aware of or may not have considered.
Source by Jon Kreski