UHF Versus VHF - Which Two-Way Radio Frequency is Much better?
UHF Versus VHF - Which Two-Way Radio Frequency is Much better
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There are two important formats for two-way radios. They are Ultra High Frequency (UHF) radio and Quite High Frequency (VHF) radio. Neither frequency band is inherently greater than the other. They every single have their pluses and minuses. Both formats are successful ways to communicate with one more individual. But how do you choose which 1 will fit your desires? Let's go more than the essential elements of both frequencies to assist you come to a decision.
Two-way radios communicate with each and every other by way of use of radio waves. Radio waves have diverse frequencies, and by tuning a radio receiver to a distinct frequency you can choose up a particular signal.
Radio waves are transmitted as a series of cycles, 1 right after the other. You will usually see the "Hz" abbreviation employed to indicate the frequency of a radio. Hertz is equal to 1 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 one,000,000 cycles per second--or 1000 kHz. The relationship among these units is like this: one,000,000 Hertz = 1000 kilohertz = one 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 distance in between the peaks of two consecutive cycles of a radio wave as an alternative of the quantity of cycles per second. Lower frequencies make a longer wavelength.
While wavelength measures distance among the peaks of cycles, frequency refers to how lengthy the measured time is amongst the "crest" and "trough" of a wave arriving at the supply. So frequency measures time rather of distance, but they are basically both saying the exact same issue.
What is important about wavelength for two-way radios is that it affects transmission range below particular circumstances. A longer wavelength as a general rule lets a radio signal travel a higher distance.
Lower frequencies or wavelengths have greater penetrating energy. That's one particular of the causes they are used for communicating with submarines. VLF radio waves (three-30 kHz) can penetrate sea water to a depth of approximately 20 meters. So a submarine at shallow depth can use these frequencies.
So from what you study above you may believe VHF is always the much better option for a two-way radio no matter exactly where you are using it. That's not necessarily true. Even although VHF has greater penetrating capabilities, that doesn't necessarily make it the far better choice for buildings. Keep in mind the conversation about wavelength above? Wavelength has a massive effect on transmission.
To explain this let's assume we are communicating from 1 side of a commercial creating to the other. In amongst these two points is a metal wall with a 3 foot door in it. Metal is an enemy to radio waves and they generally don't pass by way of it.
For our instance let's assume that the UHF wavelength the radio makes use of is about a foot and a half lengthy and a equivalent VHF radio is around 5 feet lengthy. These are in the ballpark of their usual wavelengths.
When the UHF transmits its signal the foot and a half extended wave will pass by way of the door considering that the door is wider than the wavelength. The VHF signal will be totally reflected considering that 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 extremely smaller holes. Microwaves becoming a very high frequency have wavelengths that are only various inches lengthy. The mesh keeps the microwaves trapped in the oven but it allows you to see inside mainly because light waves have a microscopic wavelength.
Just visualize walking by means of the constructing carrying a five foot wide pole. You will encounter the exact same challenges a VHF signal encounters. Now picture walking through the developing 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 particular distinction is that wireless signals will penetrate through drywall, masonry, human bodies, furniture, wall paneling, and other solid objects. All these objects will lower the signal strength even though. The far more dense the object, the more it reduces the signal. VHF will penetrate these obstacles better than UHF, but that doesn't necessarily mean that VHF is much 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 3 foot metal object in front of the transmitting radio, then VHF would win. Due to the fact the object is 3 foot wide it will completely block the UHF signal whereas the VHF signal will get around it. Lower frequencies such as VHF diffract about large smooth obstacles far more effortlessly, and they also travel a lot more effortlessly via brick and stone.
For most applications, lower radio frequencies are greater for longer range. A broadcasting Television station illustrates this. A common VHF station operates at about 100,000 watts and has a coverage radius range of about 60 miles. A UHF station with a 60-mile coverage radius demands transmitting at 3,000,000 watts.
So there is no clear choice for which is better, VHF or UHF. There is a lot of "black magic" to radio technology so it's not generally effortless to inform which will function better for your application. To support you decide on the best technology for you, more detail about every one is included beneath.
UHF Radio
UHF equipment operates in between the frequencies of 300 MHz and 3000 MHz. Until lately, it wasn't widely used. Now, the UHF radio frequency is utilized for GPS, Bluetooth, cordless phones, and WiFi.
There are a lot more obtainable channels with UHF so in much more populated regions UHF could be less most likely to have interference from other systems. If you are in an location where population is thin, VHF really should work fine for you. Not too extended ago the FCC also opened up a new VHF frequency named MURS that is so far not heavily employed in most locations. There's much more about MURS below in the VHF section. If you are in an region where interference from other radios could be an problem, UHF transmitters and receivers could be your very best selection unless you use a MURS VHF radio. UHF is greater at squeezing as a result of physical barriers like walls, buildings, and rugged landscape. Something that obstructs a radio wave, will weaken a radio signal. UHF lessens that effect. Although it could not travel as far, UHF radio waves will traverse about obstacles better than VHF.
To highlight the variations in indoor range, beneath is an excerpt from a brochure of a top two-way radio maker on the predicted range of 1 of their lines of handheld VHF and UHF two-way radios:
"Coverage estimates: At complete energy, line-of-sight, no obstructions the range is around four+ miles. Indoor coverage at VHF is roughly 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 really excellent at locating their way around walls, buildings and rugged landscape. Therefore range will be substantially lowered for VHF radios in these environments. That may not necessarily be a problem if the range required is only a couple of hundred feet. You can also add an external antenna to an indoor VHF base station that will minimize or get rid of this difficulty.
One of the downsides to UHF is that the FCC calls for you to get a license to operate in these frequencies. Despite the fact that numerous frequencies in the VHF company band also call for a license. If you select a radio in the VHF MURS frequencies you can operate it with out a license. UHF gear is normally much more pricey. The components need to have to be finely tuned and are a lot more high priced to construct. This does not imply it's necessarily far better, just more pricey.
1 advantage of UHF transmission is the physically brief wave that is produced by the high frequency. That signifies the antenna on the radio can be shorter than an equivalent VHF radio.
VHF Radio
VHF equipment operates among the frequencies of 30 MHz and 300 MHz. FM radio, two-way radios, and tv broadcasts operate in this range.
Both UHF and VHF radios are prone to line of sight aspects, but VHF a small far more so. The waves make it by way of trees and rugged landscapes, but not as effectively as UHF frequencies do. Nevertheless, if a VHF wave and a UHF wave had been transmitted over an location not having barriers, the VHF wave would travel virtually twice as far. This makes VHF simpler to broadcast more than a extended range. If you are operating largely outdoors, a VHF radio is probably the greatest selection, specifically if you are employing a base station radio indoors and you add the external antenna.
Considering that VHF has been about longer and isn't as difficult to make, equipment is typically more affordable when compared to similar UHF equipment. 1 disadvantage to this gear can be its size. Considering that the frequency waves are larger, an antenna ought to be bigger.
VHF radios also have a smaller quantity of obtainable frequencies. Interference with other radios could be additional most likely to be a difficulty. However, the FCC lately created this much less of a challenge when they opened up the MURS frequencies. The 150 MHz frequency is a Citizens Band radio spectrum that is referred to as the MURS service. MURS stands for Multi-Use Radio Service. This service is for use in the United States and Canada. It is a low energy, short range service in the VHF 150 MHz Citizens Band radio spectrum. There are 5 channels in the MURS frequencies with 38 privacy codes below every single 1 that allow you to only pick up conversations on your code. The FCC does not call for users of items for MURS to be licensed.
With MURS you can add a bigger or external antenna to improve range. If you want to place an antenna on best of your residence or business, you can do it with MURS. Some antenna producers claim an external antenna can improve the powerful radiated power of a transmitter by a factor of 4. These MURS intercoms can transmit up to four miles, and maybe additional with an external antenna depending on the terrain.
One benefit of VHF wireless radios is that battery life is nearly constantly far better than for comparable UHF units. For handheld radios this is a plus.
VHF equipment is normally lower expense for those on a spending budget. Equipment can be additional economical than related UHF merchandise.
In summary, if you are organizing on working with your two-way radios primarily within buildings, then UHF is probably the greatest resolution for you. If you are primarily working with your two-way radios for communication outside, then VHF would be a very good selection. Either radio technologies can function for you if you don't genuinely have a lengthy range to cover. In that case you may well want to decide on VHF for it's lower cost.
UHF Versus VHF - Which Two-Way Radio Frequency is Superior?
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