Question And Answer Time , Question Number one —-Whats the Difference Between UHF and VHF


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Question And Answer Time , Question Number one —-Whats the Difference Between UHF and VHF

Ok So here’s the first in the Q&A series

A question i often get asked is ,

I have a UHF CB Radio , I have some VHF commercial chan’s that i want to listen to or i want access to can you put these in my UHF  Cb This is mainly for the likes of the emergency services vols that want one radio rather than two ,i will try and keep it as simple as possible ,

The information has in parts been taken from a few different sites that best explain !

VHF (Very High Frequency) and UHF (Ultra High Frequency) come with distinct pros and cons, understanding these differences will help you identify the best signal frequency for your two-way radio needs. For instance, UHF does not travel as far as VHF but may grant higher bandwidth occupation.

VHF- Very High Frequency

Very high frequency is commonly used for FM radio broadcast, two-way land mobile radio systems, long-range data communication, and marine communications, just to name a few. VHF includes radio waves from 30 MHz to 300 MHz.

VHF waves must not exceed the local radio horizon of 100 miles. VHF frequencies are less likely to be interrupted by atmospheric noise, issues with electrical equipment, and other interferences.

There are different bands within VHF frequency, including low-band and high-band. Low-band VHF 

With so many different users the low-band VHF is not recommended for use of serious applications due to the levels of radio “noise” present at these frequencies. High-band VHF range is popular for professional applications. 

UHF- Ultra High Frequency

UHF radio waves are much shorter in length than VHF, measuring around 12 to 24 inches. As a result antenna length is reduced as well as radio range. Anything from a building to a human body can interfere with UHF transmissions. Dropouts and interference are far more likely, but greater bandwidth occupation is permitted.

UHF radio waves generally only go as far as line of sight. Anything in the way of your sight will also interfere with frequency range, such as buildings, tall trees or any other obstruction. The transmission is high enough to penetrate through building walls, making indoor reception a possibility.  It is the limited line-of-sight broadcast range that makes UHF unsuitable in some instances. VHF offers a much larger broadcast range, which is preferred in some industries.

UHF radio signals are used in many facets of life including satellite communication, GPS, Wi-Fi, Bluetooth, walkie-talkies, cordless phones, cell phones, and television broadcasting.

A large advantage of UHF transmission is the short wavelengths produced by the high frequency.  The size of the radio wave relates directly to the length of transmission as well as the reception antennas. In general, UHF antennas are short and wide.

The cost of operating UHF equipment outweighs the operation of VHF equipment.  This is because it is more work to create UHF compatible devices based on the ways high frequency and short wavelength radio signals interact together. The difference in cost largely relates to the need for antennas, cables and other additional equipment. 

Here is a few youtube videos that show this

So as you will see there are a number of differences in the VHF /UHF spectrum , and this is why the VHF radios can not be programmed with UHF chans or visa versa



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