back to article World's tallest tower in massive broadcast FAIL

The world’s tallest free-standing broadcasting tower has a slight problem – it can’t broadcast very well. The ¥65 billion (£503m) Tokyo Skytree was opened to an awe-struck public in May this year. Standing at an impressive 634 metres (the Eiffel Tower tops out at 324 metres), the idea was that in January 2013 it would take …

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  1. jake Silver badge

    This is a prime example of what happens when ...

    ... marketards attempt to do engineering.

    Honestly, the mind boggles.

    1. lightknight
      Trollface

      Re: This is a prime example of what happens when ...

      Perhaps the problem is that they are simply holding the receivers wrong? ^_^

    2. Anonymous Coward
      Anonymous Coward

      Re: This is a prime example of what happens when ...

      It doesn't work so therefore it's the marketing department's fault? Just accept that engineers arse things up sometimes.

  2. Anonymous Coward
    Anonymous Coward

    Perhaps...

    some simple common sense may have been better.

    They may have been better off, rather then trying to go for "the biggest" to instead go with a couple of smaller, so that they could cover a larger area/have some overlap?

    1. Anonymous Coward
      Anonymous Coward

      Re: Perhaps...

      you cant overlap broadcasts (wave interference causes not-spots), unless you use different frequencies, depending on what is available, will determine which is the best solution.

      1. Anonymous Coward
        Anonymous Coward

        Re: Perhaps...

        Nope. It's quite feasible in the digital world to run multiple transmitters on the same frequency. It's rather cleverly known as a Single Frequency Network (SFN) and is actually one aspect of DAB that works quite well. With the completion of UK switchover for TV and the migration of TV from 800Mhz, SFN's are now being engineered into TV as well.

        In analogue two transmitters on the same channel would cause mutual interference and black-spots, but because each "bit" of a digital transmission is like a discrete transmission at a very distinct time, other bits from other Tx's on the same frequency appear like short term echos. You just have to make sure the time interval between successive bits does not clash with the time delay from distant transmissions.

        eg. if you have a 8000 carrier digital system, carrying 8mb/s, each carrier is carrying 1000 bits per second, ie. 1ms apart. As long as distant transmitters on the same frequency are recieved with less than 1ms delay (ie. about 300km max spacing) the system works. The caveats are that frequencies must be exactly synchronised, and the same datastream must be broadcast by all transmitters and again must be in sync. Normally that requires the use of some form of GPS sync reference, though of course any form of precise timing could be used.

        1. Anonymous Coward
          Anonymous Coward

          Re: Perhaps...

          "In analogue two transmitters on the same channel would cause mutual interference and black-spots, but because each "bit" of a digital transmission is like a discrete transmission at a very distinct time,"

          Digital transmissions still use an analogue carrier which can still suffer from destructive interference with another carrier. But because digital signals generally use higher frequencies than analogue broadcasts these blackspots tend to be quite small.

          1. techmind

            Re: Perhaps...

            Since each transmission signal spans (almost) the 8MHz bandwidth, comprised of (almost) 8k carriers for TV SFNs, 'ghosting'/reflections/echoes or other distant trasmitters effectively become notches in the received frequency spectrum domain, only severely affecting a handful of the 8k carriers - which the data redundancy and error-correction flywheels over. The symbol rate is of the order 1ms (off the top of my head; this closely related to the period of the frequency-intervals between the carriers so that the Fourier transform is nicely orthogonal) so as long as echoes/reflections/distant transmissions are delayed by rather less than 1ms (the safety "guard interval" probably being about 1/4 to 1/8th ms), then intersymbol interference won't be a problem and all will be hunky-dory.

  3. Anonymous Coward
    Anonymous Coward

    it's called fascist engineering, the fcc successfully completed their conversion as well

    Once you got your swr's down, the only choice is to run some serious power.

    Hope the antenna can handle the new load.

  4. Anonymous Coward
    Anonymous Coward

    Goes to show..

    It's not the size that counts, it's what you do with it...

  5. Anonymous Coward
    Anonymous Coward

    Wow ..

    Amazing how the commentards are so insightful.

    "Those who are ignorant of their own ignorance pose the greatest danger to humanity"

  6. P. Lee
    Coat

    The solution is over their heads.

    /gone

  7. AndyS

    Costs

    So the total tower cost £503m, but rebuilding it after the earthquake cost £91.7bn?

    I'm confused. Were the marketers in charge of the whole budget?

    1. Aldous
      Headmaster

      Re: Costs

      The 91.7Bn was the overall cost of rebuild from the Tsunami, 230k of which went into promoting the tower for tourism.

  8. Cyberspice

    Emley Moor

    Even Emley Moor is taller than the Eifel Tower!

    1. MJI Silver badge

      Re: Emley Moor

      There is a song about Emley Moor, about hats or something

      1. jake Silver badge
        Pint

        Re: Emley Moor

        Baht 'at? That's Ilkla Moor.

        This Californian has been there & done that. In sleet. Was pretty narsty. Damn near caught me deeath o` cowd. But the pint & kiss at the end was tasty ... Howzat?

        Recommended, once, or several times[1]. Live a little :-)

        [1] I wasn't courting Mary Jane ... I was courting Katie G. ;-)

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