Radio Microphones (Things to consider):

These notes are written for the UK, These rules are broadly similar in the rest of Europe, but the VHF bands are often on different frequencies. Please keep this in mind if you are a touring band or entertainer. Frequencies and licensing rules vary significantly in the rest of the world.

  • For general speech work, most of the types will work well if the Mic and receiver are reasonably close together. Say 10 metres.
  • Many microphones will work effectively up to a range of 30 or more metres. The reliability reduces in buildings, especially where walls often hide metal reinforcement.
  • Use a dual diversity type if you are on the move, in a building, or not in direct line to the receiver. Steel in building walls will affect reception.
  • UHF types will provide the best results and are the choice of most broadcasters and professional entertainers. System price will be some guide to the quality of the system, but also consider, like all things, you may be paying a premium for a very famous brand.
  • Use the high quality headband mics for aerobics and any kind of exercise class teaching. Drop-outs are less of an issue here, but reliability under extreme conditions are obviously important. The specially designed head set microphones will last longer under the strains of this kind of activity, plus they are moisture resistant.
  • Breakthrough from other radio users, Taxis and so on, can be a problem on VHF radio microphones. Radio Microphones which have the option to change frequency will often overcome the problem. UHF types provide the best solution and are less susceptible to this.
  • Three or four microphones can be used simultaneously with most of the variable frequency UHF types of microphone and these can be operated in the unlicensed band.
  • If you plan to use more than two or three radio Mics simultaneously, a multi channel unit is the way forward. It will offer the flexibility you need when  upgrading in the future, so make sure your microphones can be used across all the bands you will require for the future.
  • Aerial distribution and booster units can be included in the system and this will make operation reliability assured.
  • It is not possible to use more than four microphones in the unlicensed band, even if you can select more frequencies in the allocated frequency range. This is because intermodulation problems will stop the microphones operating correctly. It is also not possible to use more than one microphone on the same frequency, when they are within range of each other.   And again you also cant use two of the lower cost four channel systems together, the frequencies will clash and cause all kinds of problems.

  • There are no short cuts to having an effective multi-channel system, you have to pay for higher priced kit and get the flexibility you need.
  • Up to 16 can be used at the same time in channel 38 if you buy a license and more channels are available if individual spot frequencies are used. These can also be made available from the licensing authority. Check the individual types for more information on what bands they operate in. See below for links to the OFCOM licensing authority.

Radio Microphone  (Licensing)

As mentioned above many radio microphones can be operated without a  license except those working on Band 38, the licensed band.

The licence free bands operate on the following frequencies:

UHF 863.1- 864.9 MHz Channel 70 & VHF173 – 175.1 MHz.

If you want to use a large number of microphones simultaneously you will have to use channels outside the unlicensed band. This is Channel 38, 606.5-613.5MHz and where you need to apply for a licence.   The licensing process is simple and is now controlled by OFCOM.

They will ensure that the correct frequencies are chosen, so as not to clash will other local users (adjacent schools and theatres etc)

The licence you need is called PMSE “Program Making & Special Events”