FM v DAB Basic Aerial Facts TV and FM aerials Historically radio...

FM v DAB Basic Aerial Facts TV and FM aerials Historically radio in the UK was always broadcast in three distinct bands, from Long Wave through Medium Wave up to VHF/FM (Very High Frequency), but in 1995 a new digital system was introduced just above the FM band. This was christened Digital Audio Broadcasting or DAB, and, unlike FM, it is transmitted on a Single Frequency Network. Also, unlike FM, packages of stations are transmitted together (a bit like the Freeview MUXES). These were originally called ensembles but often now referred to, somewhat confusingly, as MUXES. In fact, it is important not to get DAB confused with the radio channels which are transmitted as part of the Freeview package, that is a different system altogether. The frequencies of the bands (and their corresponding wavelengths) are given below : Long Wave - 148 to 283 kHz = 2020m to 1058m Medium Wave - 526 to 1606 kHz = 570m to 187m VHF/FM - 88 to 108 MHz = 3.4m to 2.8m DAB - 175 to 230 MHz = 1.7m to 1.3m This page is primarily concerned with FM/DAB aerials and reception issues, those who want to know more about the content should look on MDS975. Some of the FM aficionados who buy aerials from us assure me that FM has a superior sound quality to DAB. Personally speaking, I only tend to listen to Radio 4 and Radio 5 so I cannot really confirm this ! But if DAB follows the same pattern as the picture on Digital TV then this rumoured superiority of FM wouldn`t surprise me at all. That said, just like with Freeview TV, this supremacy of the analogue system would only apply if you have a decent signal. Those who have an imperfect signal, and/or a low-quality system, would probably find DAB superior. There is one seldom mentioned the advantage of the DAB system. I`m told that down in London, and some other big cities, there are so many pirate stations around that getting interference free FM reception can be a little frustrating, but, at the moment, the pirates haven`t cracked DAB. Some cynics reckon that the powers that be are slow timing on prosecuting the pirates to try and force people to switch to FM ! The story was that in June 2009 the Government published its “Digital Britain” report in which it said it would like to switch off all national analogue radio in 2015, but even then they were only talking national FM transmissions anyway (e.g. BBC Radio 1 to 4 and Classic FM), not local ones, and local included the BBC local radio stations. So don`t go thinking FM broadcasting was ever going to end anytime soon ! (reconfirmed by Ofcom Aug 2012). There have never been any plans to cease local radio FM transmissions. The latest twist was in December 2013, the Government abandoned any timetable to switch off an ​analogue radio, which may not come as much of a surprise to some people. Those cynics doubted the FM signal would ever be turned off because low band VHF isn`t that suitable for mobile Internet (unlike UHF), so it`s not so worthwhile for the Government who are primarily concerned how much money it`d raise, particularly as the spectrum doesn`t seem to be worth as much these days ! However the fact that radio switchover may possibly happen at some indeterminate time in the future does mean that the FM half wave dipole aerial`s relatively good performance on DAB (and the fact it can be easily cut down to improve DAB still further) is yet another point in its favour! http://tvaerialsx.co.uk

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