VHF or UHF Radio Mic – What is the Difference?

One of the most frequent questions we get on Wireless Mic System enquiries is what difference there is between VHF and UHF radio mics. This post aims to give you the basics to help understand the differences, and therefore guide you to which system would be best for you.

What do VHF and UHF mean?

The terms VHF and UHF refer to the type of carrier signal used to transfer audio signals from the microphone transmitter to the receiver. VHF stands for Very High Frequency, whilst UHF stands for Ultra High Frequency. These represent the frequency band used but in itself this does not affect the core principle of transmitting the audio signals. Many wireless manufacturers moved to UHF from VHF simply because it is possible to run more systems within UHF than VHF as the actual frequencies used are narrower. This became more common as the cost of UHF components gradually reduced and therefore more cost-effective for the consumer.

VHF Wireless Systems

Whilst most wireless manufacturers now produce UHF systems, there are still a number of VHF radio mics available on the market. These systems are the cheapest to manufacture and buy, and offer an excellent entry-point for buyers. VHF systems run in the frequency range of 173.800kHz to 175.000kHz and will usually support up to 3 mics within that range.

It is also worth noting that most VHF radio mics are fixed-frequency – that is to say that they are supplied on a specific frequency (such as 173.800kHz) and can’t be changed. Whilst for many people this will not be an issue, if there are any other wireless users nearby using the same frequency, you cannot change your own frequency to eliminate interference. So bear this in mind if you are going to be using the radio mic in a built-up area.

UHF Wireless Systems

UHF, short for Ultra Hugh Frequency, is different wireless band altogether and does not conflict in any way with radio mics in the VHF band. UHF systems are the most common available at the time of writing, and are available on a number of different Channels within the UHF Band. UHF systems take up a smaller space individually within the channel and therefore more channels can be used at the same time.

Most UHF systems are supplied as multi-frequency systems. This is to say that you can choose the specific frequency that the individual radio mic uses. Unlike fixed-frequency systems, multi-frequency radio mics will allow you to change the frequency if you start to get interference from a neighbouring wireless microphone. Individual models vary, but expect to be able to choose from 4 different frequencies right up to thousands!

UHF Wireless Channels

There is much talk at the moment about changes coming in 2012 to the allocation of UHF Channels. This is covered in our post on Channel 70 and Channel 38 so I won’t go into the detail within this post. However, it may be useful to cover the basics of what is meant by the different channels here.

There are two main UHF channels used for wireless systems in the UK. These are Channel 70 (UHF Frequencies Range of 863-865 MHz) and are available to use without a licence in the UK. The other is Channel 38 (UHF Frequency Range of 606-614 MHz) which has recently been reallocated from Radio Astronomy usage. Channel 38 allows up to around 12-16 simultaneous radio mics to be used together although this is dependent upon each model. Channel 38 mics also require a licence before use. this licence is for the whole channel, irrespective of the number of systems being used, and costs from £75.00 for a one year licence or £135.00 for a two-year licence.

For static wireless installations, such as schools, churches and theatres, it may be that a co-ordinated licence is more appropriate. These are available on other channels such as 39 or 40, and become specific to you in that area. A specific remote site survey is recommended in these circumstances, so please call us to discuss your requirements.

In Summary

Hopefully this post will have given you enough information to be able to choose the most appropriate system for your needs. For more information on individual systems, visit our Radio Microphones section on our main store site. If you have further questions, or just want confirmation that you are making the right decision, why not call us free on 0800 098 8079.

2 comments to VHF or UHF Radio Mic – What is the Difference?

  • Alastair Turnbull

    Hello

    I was recently at Heineken Cup Rugby Match. I was told, by the Sky TV techies, that the ref’s mic was using 686.550 MHz. I think this was the old TV Channel 48 (686-694 MHz). I am thinking of purchasing a scanner to listen to the referees whilst at games. Could you please tell me if this frequency range is likely to be the one used for such sporting events? It makes life a lot easier when searching. Your advice is appreciated.

    Thank you very much.

    Regards
    Alastair Turnbull

  • Both UHF / VFH really work great with out any confusion, make sure the installation process is done by professional person . The cost of UHF components gradually reduced and therefore more cost-effective for the consumer.

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