![]() ![]() However, the VHF signal is reflected since it is wider than the door. The UHF signal (1 1/2 ft) passes through the door easily. The UHF wavelength is roughly one and a half feet wide, the VHF wavelength is roughly five feet wide. ![]() In between is a metal wall with a three foot opening. Assume you are trying to communicate from one side of a commercial building to the other. Remember, UHF signals are shorter than VHF, this is important when you're in or around buildings. It's because of the difference between how VHF vs UHF signals react around structures. Not so fast.Įven though VHF can pass through obstacles better and travel farther, that doesn’t mean it's always the better choice. If a VHF wave and a UHF wave were transmitted over an area without barriers, the VHF wave would travel almost twice as far. VHF frequencies can penetrate objects better than UHF. We are often asked "Is VHF or UHF better?" Neither is inherently better, they each have strong points and weaknesses. The two frequency ranges (also called "frequency bands") used in most two-way radios are VHF (Very High Frequency), and UHF (Ultra High Frequency). But it doesn't end here, there are other considerations we need to explain. So the distance to the horizon is the maximum communication range for these two way radios, without the aide of additional equipment to "boost" the signal. Unlike frequencies below 2MHz, radio waves in these higher frequencies travel in straight lines (called "line-of-sight" signals), and generally cannot travel beyond the horizon. The two most commonly used frequency ranges for two-way radios are VHF (Very High Frequency 130-174MHz), and UHF (Ultra High Frequency 400-520MHz). Most two-way radios used today have a frequency range somewhere within 130MHz to 900MHz (except CB & Ham radios). BUT, low frequencies are susceptible to some other issues. CB radios, and some HAM frequencies, are in the HF (High Frequency) range of 29-54MHz, giving them some of these qualities. As a general rule, the lower the frequency, the greater distance it can travel. So these low frequency signals can sometimes be received by radios below the horizon hundreds of miles away. They differ in how they travel, and how they react when they encounter materials.įrequencies below 2MHz (Megahertz) are reflected off the atmosphere, thus they can follow the Earth's curvature. Let's discuss each of these.įirst, not all radio signals are the same. But taken in combination, they can mean the difference between getting 1/2 mile range, vs 6 miles or more. No single factor is a silver-bullet to extend your communication range. The key considerations that affect range are: signal type, antenna, obstructions, and signal strength (wattage). Understand the key factors affecting communication range That's because the type of equipment and terrain can greatly affect your range. Unfortunately there isn't a quick answer. "How far can this radio talk?" is one of the most common questions people ask when buying a two-way radio. So how far can you really expect to talk? This maximum range is more theoretical than realistic. The key words in the advertisement are "up to". If you search for reviews on these same radios, you will find many disappointed people saying they can't get anywhere close to the advertised range. You often see ads for two-way radios saying "up to 36 miles" or more.
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