Discovering Unknown or Unlisted Active Frequencies

One of the exciting things about radio scanning is discovering unknown or unlisted frequencies that are being used in your area or near you.

For example, I was once visiting a Raging Waters Theme Park with my family and witnessed security officers racing through a crowd and out of sight. I quickly got my scanner out of my wife’s bag and turned it on.

I already had the security frequency programmed, but did not hear anything. After a few minutes of hearing nothing, I decided to conduct a frequency search and found an unlisted frequency being used by security. It turns out that they were responding to break up a fight between several teenagers.

As you can see, this is a handy feature to familiarize yourself with. Searching for frequencies can be done in two ways.

Preprogrammed Service Search

All modern scanners come with a feature called "Preprogrammed Service Search", indicated by the “SVC” or “Search” button. This feature is handy for finding unknown or unlisted frequencies being used near you.

The Preprogrammed Service Search allows you to search through a preprogrammed range of frequencies including; Police/Fire, Marine, CB, FRS/GMRS/MURS, Aircraft, HAM/Amateur Radio, and Weather.

These ranges cover frequencies for public safety, news media, TV broadcast audio, HAM/Amateur Radio, special low power radios, railroad, marine, and much more.

You can toggle search services on and off to focus on a certain range of interest or search all at one time. In marine or CB bands, you can search or manually select a channel.

In addition, some search services such as Police/Fire and HAM bands, may have several group ranges within them.

Using Limit Search

If you scanner does not come with a Preprogrammed Service Search function, almost all have a "Limit Search" where you can set the scanner to search between a "Low" and High" range of frequencies you choose.

Common Search Ranges

Below are common search ranges from Low to High that you can manually enter and search:

• 29.000 – 50.000 MHz       Gov't, business, two-way radio.
• 50.000 – 54.000 MHz       6-meter Amateur Radio
• 108.000 – 136.000 MHz   Aircraft
• 138.000 - 144.000 MHz   Government
• 144.000 - 148.000 MHz   2-meter Amateur Radio
• 160.110 - 161.565 MHz   Railroad Operations
• 150.000 - 174.000 MHz   Shared by Business, Maritime, Weather, & Public Safety
• 406.000 – 420.000 MHz   Government
• 420.000 – 450.000 MHz   Amateur Radio
• 450.000 – 470.000 MHz   Shared by Business, Industry, Government, & Public Safety
• 470.000 – 512.000 MHz   Public Safety
• 806.000 – 940.000 MHz  “800 Band” Public Safety
• 851.000 – 866.000 MHz   Business & Public Safety
• 866.000 – 869.000 MHz  Public Safety

Keep in mind that not all scanners can receive all the bands above. Refer to your scanner's manual for details on what your scanner can and can't receive. Need a manual? Check out my previous post "Where to Find Police Scanner User Manuals".

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

-RF