Emergency Communications - Lesson 5 - What Is a Police/EMS Scanner?
A scanner, also known as a police scanner or EMS scanner, is a radio receiver that scans multiple frequencies used by:
Police departments
Fire departments
EMS
Public works
Weather alerts (e.g., NOAA)
Search and rescue teams
Utility companies
Unlike a two-way radio (like HAM), scanners only listen; they don’t transmit. They're an excellent tool for gaining real-time, local awareness during emergencies, disasters, road incidents, or civil unrest.
Why Scanners Are Valuable for Preparedness
Using a scanner can significantly improve your situational awareness, especially during emergencies. It allows you to stay informed during disasters such as wildfires, floods, and power outages by providing real-time updates directly from first responders and emergency crews. Scanners also help you track nearby incidents like car accidents, road closures, and police activity, giving you critical information that often surfaces well before it appears on news broadcasts or public alert systems. Many models also monitor NOAA weather broadcasts. This ensures you receive timely alerts about severe weather conditions. Whether you're sheltering in place, planning an evacuation, or adjusting your travel route, a scanner enables you to make smarter, faster decisions based on accurate, unfiltered information.
Using a Scanner on the Road
If you're taking a scanner on a road trip, here’s what you need to know:
Mobile or Handheld Scanners Work Across Regions
Most modern digital scanners (from brands like Uniden or Whistler) support location-based scanning via GPS or zip code input.
As you travel, the scanner can automatically update to monitor frequencies used in your current area.
Do You Need to Pre-Program It?
Yes, and No. You have two options:
Pre-program frequencies for each county or state along your route (time-consuming but precise).
Use GPS-enabled or zip code-based models, which auto-load local frequency databases as you move.
If you're using an older or analog-only model, you will need to manually program frequencies for each jurisdiction.
Digital vs. Analog
Many public safety agencies now use digital trunked systems (like P25 Phase I or II).
You’ll need a digital trunking scanner to receive those transmissions.
Analog-only scanners are increasingly limited.
NOTE on Digital Trunked System: A digital trunked radio system is a modern communication network used by many police, fire, EMS, and government agencies. Unlike older systems where each department had its own fixed frequency, a trunked system allows multiple departments to share a large pool of frequencies. A central computer assigns channels dynamically, much like a dispatcher managing multiple phone lines. This setup is efficient, reduces radio traffic congestion, and allows seamless communication between different units. However, to follow these constantly shifting conversations, your scanner must be capable of decoding the system’s digital control signals. It's important to note that while some agencies encrypt their radio traffic—especially for tactical or federal operations—many public safety departments, such as fire, EMS, and highway patrol, still use unencrypted digital trunked systems. With the right digital scanner, you can stay informed by listening to these critical broadcasts in real time.
Weather Alert Capabilities
Most good scanners include a built-in NOAA weather alert function, which:
Monitors local NOAA channels 24/7
Issues severe weather alerts (tornadoes, flash floods, blizzards, etc.)
Works even when cell towers are down
You can also buy dedicated NOAA weather radios, but a scanner with NOAA functionality gives you both emergency services and weather updates in one device.
Recommended Units
Uniden HomePatrol-2 (easy, touchscreen, GPS-ready)
Uniden BCD436HP (portable, digital, zip code input)
Whistler TRX-2 (mobile/base, P25 compatible)
Whistler WS1040 (handheld, digital, budget option)
Preparedness Tips for Scanner Use
Use GPS-enabled or zip code-based models, which auto-load local frequency databases as you move.
Keep an updated frequency database (use sources like RadioReference.com).
Mount it in your vehicle or carry it handheld depending on your use.
Use headphones or external speakers for clearer audio in noisy environments.
Understand scanner laws-some states (like NY, IN, FL, MN, KY) restrict in-vehicle use unless you’re a licensed HAM or emergency responder.
When disaster strikes, staying connected can make all the difference. This guide covered a wide range of tools, from smartphones and satellite messengers to HAM radios, scanners, and walkie-talkies. These options help you build a layered, reliable communication plan.
The key takeaway? Don’t rely on just one single device. A resilient plan includes short- and long-range options, backup power, and the ability to receive and send information, even when the grid is down.
Preparedness isn’t about fear, it’s about having options when others don’t.
