UK legal radio mic frequency guide

When using radio microphones it is important to use the right frequencies. There are different sets of frequencies suitable for different purposes. Some require a licence while others do not. The following information gives a brief guide to find the most appropriate solution.

Licence exempt frequencies – No licence required

These frequencies are available throughout the UK, indoors or outdoors, without a licence. There is availability at VHF and UHF and the frequencies are detailed below.

All new equipment should use the following frequencies:

VHF band (173.7 – 175.1 MHz)								UHF band (MHz)
173.800	174.000	174.200	174.400	174.600	174.800	175.000		863 – 865

Notes

Typically, up to 3 VHF frequencies can be used together. For example, 173.8, 174.2 and 175.0MHz.
Typically, up to 4 frequencies can be used together. For example, 863.1, 863.7, 864.1 and 864.9 MHz.
Transmitter power: 10mW (Up to 50mW permitted for body-worn pack).
VHF other users: Wireless microphones only.
UHF other users: Wireless microphones, domestic cordless headsets and loudspeakers.

Older VHF equipment may continue to use the legacy frequencies:

VHF band (173.7 – 175.1 MHz)
173.800	174.100	174.500	174.800	175.000

Wi-Fi band (2400 – 2483.5 MHz)

Wi-Fi Band (MHz)
2400 – 2483.5

Notes

Manufacturers claim up to 70 frequencies can be used together.
Transmitter power: 10mW.
Other users: Wireless computer networks (Wi-Fi), RF Tags (RFID), Bluetooth short-range links, video links, wireless microphones, microwave ovens, movement detectors, industrial control and monitoring, wireless DMX control, digital wireless intercom.

Licence exempt summary

There is the potential for interference from other radio microphones. You may find that licence exempt frequencies suit your purposes - but if you want to reduce the likelihood of interference, shared or co-ordinated frequencies may better suit.

Shared licensed frequencies – UK roaming

Frequencies dedicated for radio microphones, known as Shared, are available across the UK. A licence, which must be purchased from PMSE Licensing, is required to operate radio microphones on these frequencies.

There are VHF Shared frequencies and also UHF (Channel 38) Shared frequencies. The UK Wireless Microphone Licence does not specify spot frequencies in Channel 38 - but the 10 channel plan below will ensure that all frequencies can operate in the same location without harmful interaction. This plan is a suggestion only. Users and manufacturers can devise their own plans that could involve any number of frequencies within the range.

VHF (MHz)					UHF (Channel 38) (MHz)
175.250*	191.900	199.700	208.300	209.200	606.600	609.150	611.250	613.500
175.525*	192.800	200.300	208.600	209.600	607.500	609.950	612.300
176.600*	193.000	200.600	209.000	209.800	608.150	610.550	613.150

*Not available in Northern Ireland

RF bandwidth is limited to 200kHz. Transmitter power is limited to 10mW (Up to 50mW permitted for body-worn pack).

A licence to use all the VHF shared frequencies is £80 (£75 on-line) for one year. A licence to use all the UHF shared frequencies is £80 (£75 on-line) for one year - and £155 (£135 on-line) for two years. Two licences are required to use both the VHF and UHF frequencies. Care must be taken when using multiple frequencies from these sets. Interference problems may result from interaction between the multiple frequencies known as inter-modulation.

Licences on these frequencies are available to all users, and Shared frequencies can be liable to interference from other licensed shared radio microphones. However, they are most suitable for users who require ‘go anywhere’ radio mics, to locations where they are not likely to come across other users.

At busier locations, and to avoid the possibility of interference from other users of shared radio mics, users are advised to use Co-ordinated frequencies.

Co-ordinated licensed frequencies – for specific UK locations

Co-ordinated frequencies are licensed for specific locations by PMSE Licensing to minimise interference to the user from other licensed radio microphones and radio users. Applications for these frequencies are ‘co-ordinated’ against other assignments coinciding in frequency, geographical location and time. There are co-ordinated frequencies at VHF and UHF (470 – 790 MHz).

VHF (MHz)					UHF (Channel 21-60) (MHz)
176.400*	192.300	200.100	207.700		470 – 790
177.000*	208.100

*Not available in Northern Ireland

The frequency range 470 – 790 MHz is used for UK television broadcasting - but can also be assigned for radio microphones where they do not cause interference to television reception or are liable to suffer interference from television transmissions. The pattern of television coverage however is complex and constantly changing so contact Arqiva PMSE to determine whether given frequencies are available to be licensed at a particular location.

Licence fees for co-ordinated frequencies

£8.50 per frequency per 48 hour period – using the PMSE Licensing on-line application facility. (Or book direct with PMSE Licensing in writing – N.B. Then a minimum charge of £28 applies).

Long term (up to 1 year) annual charge available for indoor fixed sites only: £28 per frequency or £168 per UHF channel block.

Regardless of whether you use licence exempt or licensed radio microphone frequencies, multiple radio microphones used at the same location can interact and interfere with each other. This is known as intermodulation. Take particular care which frequencies you use together to avoid these problems.

This document gives only brief details of the frequencies available for radio microphones and the licence fees that apply. Further information can be found on the Ofcom website.

The Ofcom PMSE Licensing department issues licences for Radio Microphones, Talkback, Sound Links and Vision Links. It manages the radio spectrum used in the UK for Programme Making and Special Events (PMSE) and related activities.