Whats the most powerful FM and TV transmitter

fmradiotuner1fmradiotuner1 Posts: 20,476
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HI

I tried looking this up on Google but all this crap comes up about MP3 transmitters :rolleyes:

Also how far does the signal go on the most powerful FM and TV transmitters

Is it France Info 105.2 which I read was 500KW?
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  • [Deleted User][Deleted User] Posts: 910
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    Are you after the info for transmitter power or ERP from various transmitters, because several UK UHF transmitters run an ERP of 1 megawatt ( C.P, Sandy Heath etc )
    Henry
  • RakimRakim Posts: 870
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    efo wrote: »
    ...several UK UHF transmitters run an ERP of 1 megawatt ( C.P, Sandy Heath etc )

    Incorrect - Sandy Heath's, Crystal Palace's, etc transmitters do not 'run an ERP of 1 MegaWatt'... Transmitters do not have an ERP - They have an actual output power. It's the antenna system which has the ERP... ;)

    So, do you mean 'most powerful transmitter', or 'most powerful ERP'...??

    I think we've been here before, but an example of what I mean, is that, at the FM stations, whereby the ERP is 250kW (i.e. 125kW VP + 125kW HP), the transmitters actually 'run' (operate) at around 30kW. So, the ERP from the above mentioned transmitting site's TV antenna systems might be 1MW, but that's no to say the transmitters run at that power. ;)

    :)
  • fmradiotuner1fmradiotuner1 Posts: 20,476
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    I would say both which covers the most distance?
  • RakimRakim Posts: 870
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    I would say both which covers the most distance?

    Distance is governed by a number of factors, including antenna height & ERP, local topography, etc. ;)
  • RakimRakim Posts: 870
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    IIRC, at Wrotham (WRT), when the Band II antenna system was changed to mixed polarisation, the Beeb installed 2x20kW units. Belgium had something to say about that, and on checking the Beeb found WRT had an ERP of around 360kW! To fix the problem they simply replaced one of the units with a 10kW TX (making the system 30kW, not 40kW ;)).

    So, could Wrotham's 360kW (albeit a mistake, and no longer the case) be classed as the highest FM power in Britain...??
  • fmradiotuner1fmradiotuner1 Posts: 20,476
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    Rakim wrote: »
    IIRC, at Wrotham (WRT), when the Band II antenna system was changed to mixed polarisation, the Beeb installed 2x20kW units. Belgium had something to say about that, and on checking the Beeb found WRT had an ERP of around 360kW! To fix the problem they simply replaced one of the units with a 10kW TX (making the system 30kW, not 40kW ;)).

    So, could Wrotham's 360kW (albeit a mistake, and no longer the case) be classed as the highest FM power in Britain...??

    I have got Radio 1 on 98.8 in Parts of Norfolk all the way down to Summerset.
  • [Deleted User][Deleted User] Posts: 9,916
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    I have got Radio 1 on 98.8 in Parts of Norfolk all the way down to Summerset.

    And Radio 1 is only 120KW to keep the Frogs happy !
  • PowerplayPowerplay Posts: 4,690
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    The most powerful FM transmitters in the UK are:

    Wrotham - The South East of England
    Sutton Coldfield - The Midlands
    Black Hill - Central & Southern Scotland
    Winterhill - The North West of England
    North Hessary Tor - The South West of England

    Droitwich in Worcestershire is the highest powered radio TX in the UK with 500kW, this is used for BBC Radio 4 on 198kHz Long Wave!

    For Medium Wave the most powerful in Europe is RTL on 1440kHz in Luxembourg.
  • Gareth56Gareth56 Posts: 2,856
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    Am I right in thinking that these radio transmitters are pretty dangerous if you were to touch any "live" parts of them?
  • [Deleted User][Deleted User] Posts: 9,916
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    Powerplay wrote: »
    The most powerful FM transmitters in the UK are:

    Wrotham - The South East of England
    Sutton Coldfield - The Midlands
    Black Hill - Central & Southern Scotland
    Winterhill - The North West of England
    North Hessary Tor - The South West of England

    Don't you mean Holme Moss? Winter Hill is only 4KW
  • spannersspanners Posts: 973
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    In California they have the Hearst-Argyle Tower at 2000ft. Home to KCRA, KMAX, KQCA, and KSPX for a whopping total ERP of 20.1MW.
  • PowerplayPowerplay Posts: 4,690
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    Rossall wrote: »
    Don't you mean Holme Moss? Winter Hill is only 4KW

    Yes, I stand corrected :o
    I always think high power FM from the BBC Nationals came from Winter Hill because its the main TV mast.

    Where do Manchester & Liverpool get the BBC nationals on FM from?
  • [Deleted User][Deleted User] Posts: 9,916
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    Powerplay wrote: »
    Yes, I stand corrected :o
    I always think high power FM from the BBC Nationals came from Winter Hill because its the main TV mast.

    Where do Manchester & Liverpool get the BBC nationals on FM from?

    Holme Moss (and Llangollen is the strongest in Liverpool City Centre).

    The BBC NR from Winter Hill is very directional and mainly a filler for the Preston area.

    http://www.mds975.co.uk/txmaps/BBC/National/BBCWinterHill.JPG
  • RakimRakim Posts: 870
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    I have got Radio 1 on 98.8 in Parts of Norfolk all the way down to Summerset.

    Not really surprising as the transmitting stations at Tacolneston & Oxford are RBS off Wrotham... ;)

    BTW, Radio 1 from WRT is 62.5kW VP + 62.5kW HP (125kW MP), which is only 3dB down compared to Wrotham's other national transmissions (125kW = 21dBW. 250kW = 24dBW) The difference in service area is very little. ;)
  • RakimRakim Posts: 870
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    Powerplay wrote: »
    Droitwich in Worcestershire is the highest powered radio TX in the UK with 500kW, this is used for BBC Radio 4 on 198kHz Long Wave!

    For Medium Wave the most powerful in Europe is RTL on 1440kHz in Luxembourg.

    If we're taking AM in to account as well, did someone forget the MW transmissions from Orfordness, Suffolk, plus the VT Communications sites which transmit on SW... ;)

    BTW, the BBC tend to state (or at least used to state) transmitter output power for AM transmissions, where as commercial radio/Ofcom tend to state EMRP. A good example of this is 1458kHz from Brookmans Park... BBC GLR used to be quoted as being around 50kW (i.e. TX o/p), where as Sunrise is quoted as being around 125kW (i.e. ERMP).... ;)

    BTW, I may be wrong, but I think there's a 2MW LW mast in Poland (it may be Russia). I might be wrong... The grey matter isn't what it used to be.
    (It's been fried by too many antenna systems... lol! :D)
  • HiZHiZ Posts: 177
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    Gareth56 wrote: »
    Am I right in thinking that these radio transmitters are pretty dangerous if you were to touch any "live" parts of them?

    Yes your right!
  • Nick_GNick_G Posts: 5,137
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    Powerplay wrote: »
    The most powerful FM transmitters in the UK are:

    Wrotham - The South East of England
    Sutton Coldfield - The Midlands
    Black Hill - Central & Southern Scotland
    Winterhill - The North West of England
    North Hessary Tor - The South West of England

    Droitwich in Worcestershire is the highest powered radio TX in the UK with 500kW, this is used for BBC Radio 4 on 198kHz Long Wave!

    For Medium Wave the most powerful in Europe is RTL on 1440kHz in Luxembourg.

    Don't forget Wenvoe and Tacolneston as well. These also put out 250 kW ERP and again cover huge areas.
  • Rabbit RabbitRabbit Rabbit Posts: 331
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    Rakim wrote: »
    125kW = 21dBW. 250kW = 24dBW

    Whilst you are usually pretty good, would you like to have another go at this one? ;)
  • Rabbit RabbitRabbit Rabbit Posts: 331
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    Redcoat wrote: »
    The Taldom long wave transmitter on 261kHz (situated about 70 miles north of Moscow) has an ERP of 2.5MW and is the most powerful AM transmitter in the world. I can get it on a very good night if I can null away RTÉ Radio 1 on 252kHz.

    Whilst it may well officially have that figure, I doubt very much that it is still operating at full power; many of the ex-Soviet mega medium wave power transmitters are a shadow of what they used to be for a variety of reasons, mainly technical failure though reducing the power to reduce power consumption is very common. A lot of the transmitters have Russian made valves which have a relatively low life so are under-run to keep them going. These days some have been modified to use Eimac or Thales vales and get 10 times the valve life - but cost real money as when a Russian valve failed they took it apart and replaced what was broken.

    There's a system in Tajikistan that uses a high power transmitter and something like 26 masts to form a highly directional aerial - the problem is that the aerial was designed in Soviet days and when the Russians left they also took the paperwork so no-one knows exactly how it works, nor how to adjust it as it is off tune somewhere.

    And for high power long wave, there was the Middle Eastern state who built a high power long wave so the Royal family could listen to their radio station wherever they were in the Gulf.

    Redcoat wrote: »
    .

    During the Cold War, Radio Moscow once did some very high powered tests on short wave aiming transmissions towards the USA Eastern Seaboard back in the 1980's, the directional ERP was around 5MW which they slowly built up to. When they got to 5MW they noticed that reception in Washington DC was worse than what it was at around 2MW. ......... The Soviets decided from their tests that the highest ERP that is useful for short wave broadcasts was around 1250kW, anything stronger either made no difference or resulted in worse reception at the target area.

    I wasn't sure that this was right - many international broadcasters use 250kW short wave transmitters and a decent HRRS 4/4 array (4 dipoles high, 4 dipoles high with a reflector) can give a gain of between 15dB and 18dB so the erp is in the region of 10MW; 500kW transmitters are reasonably common as well, which doubles the erp. In the 1980s, broadcasters were replacing their services with 500kW transmitters but came to realise that they didn't really need that as if everyone was upping their power, there was no real gain so powers dropped to the 250/300kW level. And it cost a lot.
    Redcoat wrote: »
    .
    The principle behind the unintended side effect of these tests is being used by the USA for HAARP.

    Reading the article, I see that the aerial has a gain of 31dB with "a total of 3.6 MW of transmitter power" so this is 3600 MW erp (roughly with 30dB gain) so a few hundred times that of the broadcast short wave transmitters. A similiar system was built at Orfordness - the Cobra Mist system for over the horizon radar
  • RakimRakim Posts: 870
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    Rakim wrote: »
    125kW = 21dBW. 250kW = 24dBW
    Whilst you are usually pretty good, would you like to have another go at this one? ;)

    Oops... those dBW figures I gave were for 125W and 250W respectively. ;)
    (who forgot they were talking about kiloWatts, not Watts... See, I was right, my brain has been fried by too many antenna systems... :D)

    Of course, the correct dBW figures are...
    • 125kW = 51dBW
    • 250kW = 54dBW
    (30dB makes all the difference) ;)
  • smorrissmorris Posts: 2,084
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    Rakim wrote: »
    BTW, Radio 1 from WRT is 62.5kW VP + 62.5kW HP (125kW MP)
    Quick question...

    Am I right in thinking that the better measure of the likely service area of a transmitter is the higher of the two vertical/horizontal components, rather than the sum of the two?

    I believe in the USA they measure it that way, which means that they would describe our mixed polarisation transmitters as being considerably less powerful than we do... (i.e. they'd describe Radio 1 from Wrotham as 62.5kW, not 125kW)
  • smorrissmorris Posts: 2,084
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    I'm fairly convinced that the most powerful FM transmitters in the world operating right now are in Italy. They are almost all undocumented, however.

    RDS on 95.5 from Monte Bisbino (near Como) has been described as having a 20kW TX plugged into a 5x4 array of 20 vertical yagis pointing at Milan. I don't think that's enough information to figure out the actual ERP, but the information claimed it was "about 1MW".

    I did notice when staying in Venice once that a lot of the signals coming from Monte Barbaria (actually 50 miles or more away, although line of sight) came in with strengths I'd more normally expect to find within maybe five miles of a UK high power transmitter site.
  • lundavralundavra Posts: 31,790
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    Don't forget that most high power transmitters consist of several lower powered ones combined together, this makes it easier to get the power levels and also the service continues at lower power if one fails.
  • [Deleted User][Deleted User] Posts: 213
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    The BBC has a number of 250kW FM transmitters in the UK.

    In England:
    http://www.bbc.co.uk/reception/transmitters/radio/england_fm.shtml
    Holme Moss 98.9 89.3 91.5 93.7 M 250kW SE095041
    Rowridge 98.2 88.5 90.7 92.9 M 250kW SZ447865
    Sandale 97.7 88.1 90.3 92.5 M 250kW NY266398
    Sutton Coldfield 97.9 88.3 90.5 92.7 M 250kW SK113003
    Tacolneston 99.3 89.7 91.9 94.1 M 250kW TM131958
    Wenvoe(see also Wales) 99.5 89.9 92.1 94.3 M 250kW ST110742
    Wrotham - 89.1 91.3 93.5 M 250kW TQ595604

    And in Wales:
    http://www.bbc.co.uk/reception/transmitters/radio/wales_fm.shtml
    Blaenplwyf 98.3 88.7 90.9 104.0 93.1 M 250kW SN569756
    Wenvoe 99.5 89.9 92.1 94.3 96.8 - M 250kW ST110742

    And in Scotland:
    http://www.bbc.co.uk/reception/transmitters/radio/scotland_fm.shtml
    Black Hill 99.5 89.9 92.1 95.8 94.3 - M 250kW NS828647
    Sandale 97.7 88.1 90.3 92.5 94.7d - M 250kW NY266398

    And Northern Ireland:
    http://www.bbc.co.uk/reception/transmitters/radio/n_ireland_fm.shtml
    Divis 99.7 90.1 92.3 - 94.5 M 250kW J286750

    And the big daddy of them all. of course, is Radio 4 long wave:
    http://www.bbc.co.uk/reception/transmitters/radio/medium_long_wave.shtml
    Droitwich 198 500kW SO929663
  • smiffjsmiffj Posts: 245
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    Gareth56 wrote: »
    Am I right in thinking that these radio transmitters are pretty dangerous if you were to touch any "live" parts of them?

    If you touch even the antenna that transmits the tv, digital, sound ect You are sure to get what is called an RF electric shock.

    Transmitter will have to be switched off if the antenna needs adjusting.
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