There are two major formats for two-way radios. They are Ultra High Frequency (Uhf) radio and Very High Frequency (Vhf) radio. Neither frequency band is inherently better than the other. They each have their pluses and minuses. Both formats are effective ways to relate with other person. But how do you decide which one will fit your needs? Let's go over the key components of both frequencies to help you decide.
Two-way radios relate with each other straight through use of radio waves. Radio waves have distinct frequencies, and by tuning a radio receiver to a specific frequency you can pick up a specific signal.
Handheld Portable Tv
Radio waves are transmitted as a series of cycles, one after the other. You will always see the "Hz" abbreviation used to indicate the frequency of a radio. Hertz is equal to one cycle per second.
Radio waves are measured by kilohertz (kHz), which is equal to 1000 cycles per second, or megahertz (Mhz), which is equal to 1,000,000 cycles per second--or 1000 kHz. The relationship between these units is like this: 1,000,000 Hertz = 1000 kilohertz = 1 megahertz.
You may also hear the term "wavelength" when you hear about radio waves. This term is from the early days of radio when frequencies were measured in terms of the length between the peaks of two consecutive cycles of a radio wave instead of the whole of cycles per second. Lower frequencies furnish a longer wavelength.
While wavelength measures length between the peaks of cycles, frequency refers to how long the measured time is between the "crest" and "trough" of a wave arriving at the source. So frequency measures time instead of distance, but they are essentially both saying the same thing.
What is principal about wavelength for two-way radios is that it affects transmission range under sure conditions. A longer wavelength as a normal rule lets a radio signal voyage a greater distance.
Lower frequencies or wavelengths have greater penetrating power. That's one of the reasons they are used for communicating with submarines. Vlf radio waves (3-30 kHz) can jab sea water to a depth of approximately 20 meters. So a submarine at shallow depth can use these frequencies.
So from what you read above you may think Vhf is always the better selection for a two-way radio no matter where you are using it. That's not necessarily true. Even though Vhf has better penetrating capabilities, that doesn't necessarily make it the better selection for buildings. Remember the conversation about wavelength above? Wavelength has a big impact on transmission.
To expound this let's assume we are communicating from one side of a industrial construction to the other. In between these two points is a metal wall with a three foot door in it. Metal is an enemy to radio waves and they typically don't pass straight through it.
For our example let's assume that the Uhf wavelength the radio uses is about a foot and a half long and a similar Vhf radio is colse to five feet long. These are in the ballpark of their normal wavelengths.
When the Uhf transmits its signal the foot and a half long wave will pass straight through the door since the door is wider than the wavelength. The Vhf signal will be totally reflected since it is wider than the opening to the door.
Your microwave oven is an example of this. The glass front door has a metal mesh with very small holes. Microwaves being a very high frequency have wavelengths that are only any inches long. The mesh keeps the microwaves trapped in the oven but it allows you to see inside because light waves have a diminutive wavelength.
Just dream walking straight through the construction carrying a five foot wide pole. You will encounter the same challenges a Vhf signal encounters. Now dream walking straight through the construction with a pole that's only a foot and a half wide like a Uhf wave. There are lots fewer doorways you couldn't get through.
The one contrast is that wireless signals will jab straight through drywall, masonry, human bodies, furniture, wall paneling, and other solid objects. All these objects will sacrifice the signal drive though. The more dense the object, the more it reduces the signal. Vhf will jab these obstacles better than Uhf, but that doesn't necessarily mean that Vhf is better for indoor applications as we will talk about in the Uhf section below.
In our example above we assumed you had a metal wall with an opening. If you reverse this and you have a three foot metal object in front of the transmitting radio, then Vhf would win. Since the object is three foot wide it will totally block the Uhf signal whereas the Vhf signal will get colse to it. Lower frequencies such as Vhf diffract colse to large plane obstacles more easily, and they also voyage more beyond doubt straight through brick and stone.
For most applications, lower radio frequencies are better for longer range. A broadcasting Tv center illustrates this. A typical Vhf center operates at about 100,000 watts and has a coverage radius range of about 60 miles. A Uhf center with a 60-mile coverage radius requires transmitting at 3,000,000 watts.
So there is no clear selection for which is better, Vhf or Uhf. There is a lot of "black magic" to radio technology so it's not always easy to tell which will work better for your application. To help you decide on the best technology for you, more information about each one is included below.
Uhf Radio
Uhf tool operates between the frequencies of 300 Mhz and 3000 Mhz. Until recently, it wasn't widely used. Now, the Uhf radio frequency is used for Gps, Bluetooth, cordless phones, and WiFi.
There are more ready channels with Uhf so in more populated areas Uhf may be less likely to have interference from other systems. If you are in an area where population is thin, Vhf should work fine for you. Not too long ago the Fcc also opened up a new Vhf frequency called Murs that is so far not heavily used in most areas. There's more about Murs below in the Vhf section. If you are in an area where interference from other radios may be an issue, Uhf transmitters and receivers could be your best selection unless you use a Murs Vhf radio. Uhf is better at squeezing straight through corporal barriers like walls, buildings, and rugged landscape. Anyone that obstructs a radio wave, will weaken a radio signal. Uhf lessens that effect. Though it may not voyage as far, Uhf radio waves will traverse colse to obstacles better than Vhf.
To highlight the differences in indoor range, below is an passage from a brochure of a prominent two-way radio maker on the anticipated range of one of their lines of handheld Vhf and Uhf two-way radios:
"Coverage estimates: At full power, line-of-sight, no obstructions the range is approximately 4+ miles. Indoor coverage at Vhf is approximately 270,000 sq ft and 300,000 sq ft at Uhf. Expect about 20 floors vertical coverage at Vhf and up to 30 floors at Uhf. Note: Range and coverage are estimates and are not guaranteed."
Vhf waves are not very good at finding their way colse to walls, buildings and rugged landscape. Therefore range will be significantly reduced for Vhf radios in these environments. That may not necessarily be a question if the range needed is only a few hundred feet. You can also add an external antenna to an indoor Vhf base center that will sacrifice or eliminate this problem.
One of the downsides to Uhf is that the Fcc requires you to get a license to control in these frequencies. Although many frequencies in the Vhf enterprise band also need a license. If you pick a radio in the Vhf Murs frequencies you can control it without a license. Uhf tool is ordinarily more expensive. The components need to be finely tuned and are more high-priced to construct. This does not mean it's necessarily better, just more expensive.
One benefit of Uhf transmission is the physically short wave that is produced by the high frequency. That means the antenna on the radio can be shorter than an equivalent Vhf radio.
Vhf Radio
Vhf tool operates between the frequencies of 30 Mhz and 300 Mhz. Fm radio, two-way radios, and television broadcasts control in this range.
Both Uhf and Vhf radios are prone to line of sight factors, but Vhf a diminutive more so. The waves make it straight through trees and rugged landscapes, but not as well as Uhf frequencies do. However, if a Vhf wave and a Uhf wave were transmitted over an area without barriers, the Vhf wave would voyage approximately twice as far. This makes Vhf easier to broadcast over a long range. If you are working mostly outdoors, a Vhf radio is probably the best choice, especially if you are using a base center radio indoors and you add the external antenna.
Since Vhf has been colse to longer and isn't as complex to make, tool is ordinarily cheaper when compared to similar Uhf equipment. One disadvantage to this tool can be its size. Since the frequency waves are bigger, an antenna must be bigger.
Vhf radios also have a smaller whole of ready frequencies. Interference with other radios could be more likely to be a problem. However, the Fcc recently made this less of a question when they opened up the Murs frequencies. The 150 Mhz frequency is a Citizens Band radio spectrum that is called the Murs service. Murs stands for Multi-Use Radio Service. This assistance is for use in the United States and Canada. It is a low power, short range assistance in the Vhf 150 Mhz Citizens Band radio spectrum. There are 5 channels in the Murs frequencies with 38 privacy codes under each one that enable you to only pick up conversations on your code. The Fcc does not need users of products for Murs to be licensed.
With Murs you can add a larger or external antenna to heighten range. If you want to put an antenna on top of your house or business, you can do it with Murs. Some antenna manufacturers claim an external antenna can growth the effective radiated power of a transmitter by a factor of 4. These Murs intercoms can forward up to four miles, and maybe more with an external antenna depending on the terrain.
One benefit of Vhf wireless radios is that battery life is approximately always better than for similar Uhf units. For handheld radios this is a plus.
Vhf tool is ordinarily lower cost for those on a budget. tool can be more frugal than similar Uhf products.
In summary, if you are planning on using your two-way radios in general inside buildings, then Uhf is likely the best explication for you. If you are in general using your two-way radios for communication outside, then Vhf would be a good choice. Either radio technology can work for you if you don't beyond doubt have a long range to cover. In that case you may want to pick Vhf for it's lower cost.
Uhf Versus Vhf - Which Two-Way Radio Frequency is Better?