Paul Gill, principal engineer at JFMG Ltd explained: "The old frequencies were creating frustration for users who found that we couldn't issue a licence at many venues due to the risk of causing interference to TV reception. With the increasing popularity of the BTR wireless intercom it was imperative to find a solution that better meets the needs of the industry but safeguards other services."
The foundations for this breakthrough were presented at a meeting recently hosted by Orbital at their central London HQ. Given clear understanding of the operational deployment and the equipment's technical characteristics by Orbital's head of communications, Tim Sherratt, JFMG set to work. Gill commented: "It was clear that we would have to work with existing frequency bands as a new variant of the BTR would be impractical and would leave existing users stranded. Even so, I was confident that a huge improvement could be achieved by simply re-organizing the channel map on two fronts. Firstly to achieve greater flexibility - the old plan was often unable to make use of the spectrum that was actually clear for use at a particular location. Secondly to move BTR frequencies into what we call 'sweet-spots' of the TV channel. These are small sub-bands or slots within a TV channel, perhaps only 2MHz wide, in which analogue TV receivers have the greatest immunity to interference."
The framework of the new plan was embraced by BTR's US manufacturers, RTS Telex, who have provided new compatible frequency groups, which will be the basis for all new UK sales orders. Orbital will re-programme earlier systems, converting them to the new plan, enabling existing users to also benefit from the added flexibility.
Gill further explained: "For indoor stage and studio use the availability throughout the country is now excellent. We carefully select the right channel group for each location and licensing should no longer be seen as an obstacle, but more as an essential part of the planning for a successful production".
Since 1997 JFMG Ltd has been contracted by Ofcom (previously Radiocommunications Agency) to manage and license the segment of the radio spectrum that is used for programme making and special events (PMSE) in the UK. This affects radio microphones, in-ear monitors, stage intercom and studio talkback systems that all share the frequencies, which are allocated for TV broadcasting. (Sarah Rushton-Read)
