Understanding the Airwaves for Preppers, Homesteaders, and Everyday Operators
Introduction
If you’ve ever looked at a radio display and seen a jumble of numbers like 146.520 or 462.675, you might’ve wondered:
What do these numbers actually mean?
Welcome to Radio Frequencies 101 — a foundational guide that strips away the jargon and gives you exactly what you need to understand how frequencies work, why they matter, and how to use them to your advantage.
Whether you're brand new to radios or just need a refresher, this article will get you dialed in.
What Is a Radio Frequency?
A radio frequency is the specific electromagnetic wave your radio uses to send or receive signals. It’s measured in megahertz (MHz) — and each frequency represents a unique slice of the radio spectrum.
Think of it like a channel on a highway. Each one is a lane — but only people on the same lane (frequency) can hear each other.
Example:
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146.520 MHz = A common HAM simplex frequency
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462.675 MHz = A GMRS repeater-capable channel
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162.400 MHz = NOAA Weather Radio
The Radio Spectrum: An Overview
Here’s how the radio spectrum breaks down for most civilian users:
| Band Name | Frequency Range | Common Use |
|---|---|---|
| HF | 3 – 30 MHz | Long-distance HAM radio |
| VHF | 30 – 300 MHz | HAM (2m), marine, aircraft |
| UHF | 300 – 1000 MHz | GMRS, FRS, HAM (70cm) |
Key Ranges to Know:
HF (High Frequency)
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Long-range comms (hundreds to thousands of miles)
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Used by advanced HAM operators
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Bounces off the atmosphere (skip propagation)
VHF (Very High Frequency)
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Medium range, great in open areas
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Less building penetration than UHF
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Common for HAM (2-meter), marine, aviation
UHF (Ultra High Frequency)
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Best for urban and indoor use
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Great penetration through walls and buildings
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Used in GMRS, FRS, business, and 70cm HAM
Licensed vs Unlicensed Frequency Bands
| Radio Type | Licensing Required? | Band(s) Used |
|---|---|---|
| FRS | No | UHF (462–467 MHz) |
| GMRS | Yes (no test) | UHF (462–467 MHz) |
| HAM | Yes (test required) | HF, VHF, UHF |
| MURS | No | VHF (151–154 MHz) |
| CB Radio | No | HF (27 MHz band) |
Note: Even if a radio can transmit on a certain frequency, that doesn't mean it's legal for you to do so without the proper license. Always follow FCC rules.
What Is a Frequency Pair or Offset?
For radios that use repeaters (like GMRS or HAM), you may see two frequencies listed:
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Transmit frequency (what your radio sends)
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Receive frequency (what you listen to)
This is called a split or offset, and it allows your radio to send and receive on slightly different frequencies — which is how repeaters work.
Example:
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Transmit: 146.120 MHz
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Receive: 146.720 MHz
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Offset: +0.6 MHz
Your radio automatically switches between the two when programmed correctly.
What Frequencies Should You Know?
Here are some practical, commonly used ones for preppers, hikers, and homesteaders:
| Purpose | Frequency | Notes |
|---|---|---|
| HAM simplex (VHF) | 146.520 MHz | National calling frequency (2m) |
| HAM simplex (UHF) | 446.000 MHz | UHF national simplex freq (70cm) |
| GMRS Channel 16 | 462.575 MHz | Good GMRS range + repeater capable |
| NOAA Weather Radio | 162.400–162.550 | Receive-only; essential for alerts |
| MURS Channel 3 | 151.940 MHz | Unlicensed, good for low-traffic use |
How to Find Frequencies That Work in Your Area
Use these tools:
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RepeaterBook.com — Free directory of HAM and GMRS repeaters
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RadioReference.com — Local scanner frequencies (police/fire/EMS)
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Local HAM clubs — Often publish local frequency lists
Pro Tip: Create a frequency cheat sheet with your most-used channels, repeaters, and simplex frequencies and laminate it for your radio bag.
Final Thoughts
Understanding frequencies doesn’t have to be complicated. You don’t need to memorize the entire radio spectrum — just learn the bands that apply to your gear and your goals.
Once you grasp the basics of how frequencies work, programming and operating your radio becomes way easier — and way more effective in the field.