To begin with, the terms UHF and VHF are self-evident, at least in a minimalist sense. That is to say that VHF stands for ‘Very High Frequency and UHF stands for “Ultra High Frequency”.
That by definition implies that both differ primarily in their kind on the basis of their frequencies; with communication devices operating on UHF using significantly radio frequency than its counterpart ‘VHF’.
Communication systems are designed to work by transmitting and receiving certain frequencies. Those devices using VHF use electromagnetic frequencies that range from 30 MHz to 300 MHz while devices and equipment using the UHF band work on frequencies that range from 300 Mhz to 3 GHz.
Each frequency band that is UHF and VHF have their own pros and cons, especially when it comes to their practical use in the domains of science and technology.
Difference between UHF and VHF Frequencies
The beginning of low band VHF ranges from 30MHz. This frequency is used by several gadgets and devices, not just by wireless microphones and telephone communication, but also by walkie talkies and radio-controlled toys.
The range from 54-72 MHz is mostly constrained by physical factors and the 72 MHz is used by assistive learning wireless systems. 76-88MHz are given to different television channels whilst 88- 108MHz is for radio broadcasting bands.
The scattering effect of these Radio Frequency waves through the air is exceptional as they are able to pass through different kinds of non-metallic substances, a feature not afforded to that equipment using UHF.
All of this is due to the very wide wavelengths that can range from 9ft to 20ft. And the best part about it is that its cost effective relative to using UHF.
As for assistive listening devices, low bands of VHF are not advisable for noteworthy applications and that is due to a large number of users it has and the noise that it has to face, making it vulnerable to interferences. The transmitter’s power is usually less than 50mW except for in 72-76MHz range, where 1 watt is applicable for listening systems.
High band VHF is used for professional applications through quality microphone systems that are widely available in the market. High band VHF frequency has been further divided into two categories, one that is used by the general public; also known as traveling frequencies.
The main use of traveling frequencies is to be incorporated into business bands and government operations such as hydroelectric power stations, coast guards and forestry. General Radio Frequency noise is far stronger in this band than others due to limitations present within the bandwidth.
The larger part of the VHF ‘high band ‘ranges from 174MHz to216MHz and its usage includes propagation of TV (television) signals. At these frequency ranges, the television signal’s audio quality begins to suffer from a further increase in frequency.
Although high quality audio is still possible within without breaking the rules laid out by the country’s broadcasting agencies. The chances of interference from other users and noise still prevails, however it is less likely to occur within low band VHF frequencies and more in high band VHF frequencies.
UHF region contains different bands, similar to VHF in away. These bands are used for microphone systems. Major characteristics of the UHF waves is that their wavelength is shorter than 12 to 24 inches. And due to the short wavelength, antennas are required to be shorter as well.
However, there is a reduce in wave propagation through both air and nonmetallic substances, which includes human beings, doors and walls along with many other objects. This essentially means that any physical obstruction can prevent the UHF wave from reaching its target.
One of the major downsides is the increase in radio wave reflections that occur due to smaller metal objects, eventually causing severe interference.
As per the regulations for users, they require a license to operate UHF bands in a manner to obtain the right equipment. FM signals present within UHF bands have greater bandwidth. Which allows an increase in the frequency range and wider dynamic of the audio signal. In conclusion, UHF has a massive microphone system as compared to VHF high band. This feature allows many microphones to work at the same time.
The use of increased transmitter powers is not common due to the decrease in battery life and an increase in mutual system interference. The major economic difference between VHF and UHF bands is the cost of equipment and UHF beats VHF.
The machinery is costly to build. Several factors result in ultra-high frequency with significantly shorter wavelengths being economically more feasible to employ as a standard for devices. The difference in cost is mainly due to cables, antennas and other mechanisms including transmitters and receivers.
The low band UHF frequency is taken as two overlapping bands. The significant uses of these bands are for businesses such as mobiles and pagers. As for high bands in UHF; different television channels are allotted different frequencies by licensing authorities.
Minimum 1/3 wavelength antenna is required as UHF radio waves that range from 4-7 inches. The equipment is expensive and within that a diversity in systems is recommended since it provides high quality audio that is audible and achieved through a number of different systems, all working together.
High band UHF range above 900MHz and includes studio to transmitter links and other uses. There isn’t much difference between the two frequencies besides a few factors. Otherwise, both lay on the same scale on different spots. One of the major differences is their cost and how they work, their mechanics are different and devices that are used on these frequencies vary in their respective functions.
Another major difference between UHF and VHF is that VHF is able to pass through metallic substances whilst the other one can not. VHF is known to be more imperceptible however UHF tends to face more noise and interference. Even though the kind of devices and equipment used for each has been designed in a different manner.