Using Radio Mics
Radio Mics by Mary Milton
Radio mics, what would we do without them? They've become a tool that we take very much for granted, meaning almost all productions use them. The type of quick turnover television we're now used to has become very reliant on them whether they're used by a sound recordist, camera person or a researcher / AP ‘doing’ the sound.
The same technology is also used for wireless links to camera, in-ear monitoring and of course the dozens of mics used on West End shows. Radio microphone frequencies, unless you are a sound recordist are likely something that you never think about. If you work on a programme that involves multiple crews you might see a gaggle of recordists clustered around their electronic handbags first thing in the morning and wonder what they are doing. Other than gossiping they will most likely be working out how to divide the frequencies that work together between the crews that need them. It’s an essential bit of preparation, often transparent to anyone else that helps a shoot run smoothly.
Using Radio Mics in the UK
In the UK certain radio frequencies are currently available for use of radio mics. A few are intended to be for the exclusive use of radio mics and a licence is needed to use them. Once licenced they can be used all over the country. Most notably these frequencies are on UHF 859.75 - 862.00MHz (known as channel 69) and a small set of VHF frequencies around 200Mhz. Licences currently last one or two years and can be obtained from the Joint Frequency Management Group (JFMG)
If you purchase radio mics for your company or your own use on these frequencies you need to purchase a licence also. If you hire radio mics on these frequencies the hire company's licence will cover you, they should be able to provide you with a certificate to prove that you are covered.
If you're buying radio mics, bear in mind that channel 69 will no longer be available as of the end of 2012. (See my other radio mic article for more information on this)
There are also other frequencies that can be used and licensed for short or long periods. Which frequencies are available depend on the area of the UK so check with JFMG for details
Licence exempt frequencies
Lastly for the UK there are a small number of licence exempt frequencies:
173.700 - 175.10 & 863.00 - 865.00 (known as channel 70). Remember if you use these, any number of other people could be trying to use them too so the likelihood of interference is increased.
Using Radio Mics abroad
If you need to use radio mics abroad you must check that you have the correct frequencies and you should get a licence if you need one. In particular there are many places in the world where channel 69 is unusable, particularly the USA where the useable frequencies vary from state to state. It may not be as simple as taking the mics you use in the UK so ask your sound recordist to check and if necessary be prepared to hire in appropriate mics.