The UHF means ultra-high frequency and is nothing but frequencies that the radios transmit. Identifying the communication range of a UHF radio can be quite difficult. As there are many variables that can affect this range of UHF radio broadcast.
We have to identify and check what can hinder or enhance the range of the transmission in a UHF radio. Here are some factors that can make you determine the range of UHF transmission.
The Line of sight:
Whenever we discuss the UHF range it is very essential to understand the term line of sight path or line of sight propagation.
The perfect two way radio transmission’s optimal range would be the one, which provides a clear shot between one person standing on a mountain top and the other who is standing below, or can be on a different hill top.
The distance between the radio to radio lines in a transmission path is known as line of sight. As the range gets better so does the line of sight get clearer and vice versa.
When obstructions and obstacles like big trees, tall buildings, high rise walls, hills or mountains come in the path of line of sight the range shortens considerably.
On a curved planet traveling a straight course:
The shorter radio waves that travel in concentric circles in the range of 3000 MHz or 300 MHz to 3GHz frequency range are known as UHF.
The UHF waves are much shorter than the VHF waves, this gives them wattage or power that is enough to travel inside the building with ease and these can also penetrate non-metallic objects both outdoors and indoors.
One more thing that makes the UHF waves unique is that they travel in a straight line most of the time, unless they are reflected or bounced by objects in between the path. Since the earth is curved and the UHF waves straight they are both in contrast.
So if these waves are not stopped these would cross the earth’s horizon and go into space. This is why the radio antenna or a person standing on a mountain with a two way transceiver intercepts this straight line.
A helpful formula exists for computing the line-of-sight separation to the horizon: horizon in kilometers = 3.569 occasions the square root of the antenna height in meters. Utilizing a calculator we can take out the formula.
A 6-foot antennae (or somebody 6 feet tall holding an UHF two-way radio) approaches 1.83 meters. The square root of 1.83 equivalents 1.35. 1.35 increased by 3.569 equivalents 4.83 meters to the horizon, or – adjusted – 3 miles. Utilizing line-of-sight, the horizon is 3 miles from a 6-foot antennae.
Include another upstanding 6-foot antennae in an orderly fashion 3 miles from the horizon point we simply determined, and you can hypothetically send and get transmissions from the main antennae to the second antennae for a sum of 6 unhampered miles of “radio horizon.”
A scope of 4 to 6 miles is normal for a moderately made line-of-sight way. Include obstacles or obstruction, and most UHF two-way radios have a practical scope of between 1 to 4 miles.
How can we increase or maximize the transmitting or communication range of UHF radios?
The communication range of the UHF radio can be increased in the following ways:
Keeping away as much as possible from the structures and buildings made of metal: We now know that the UHF frequency can be decreased by the obstacles. So if we can just keep away from these obstacles, especially made of metals, we can enhance the range of the UHF radios.
Keeping the radio to the maximum height possible: By keeping the radio at a higher ground, mountain or anyplace elevated from the earth, we can greatly increase the communication range of the UHF radios.
By eliminating interference or using an unused channel: Using an unused channel we can greatly increase the range as there would be nil traffic and we would get a better quality.
By using fully charged or new radio batteries: Weaker or dull batteries mean weak and dull transmission. It can greatly reduce the frequency range and communication range of the UHF radio. So you must always use well charged or new batteries while operating the UHF radio.
Utilizing the repeater to enhance the range: A repeater receives a frequency and the re-send or transmits the frequency, usually with much more power and from an enhanced location, to provide an advanced and hyped up communications frequency range. This is placed on the top of a high mountain or a tall building, UHF repeaters increase the operating range of UHF radios.
Now we know that the range of the UHF radio is not a definite value but keeps on changing according to various elements.
Although now we know that the frequency or the communication range can be enhanced for better transmission in a UHF radio.