Fixing a time delay between wto Freeview boxes

Discussion in 'Computer Information' started by Bazzer Smith, Sep 10, 2006.

  1. Bazzer Smith

    Bazzer Smith Guest

    I have a freeview box and a freeview dongle (for my PC),
    however they take different times to process the signals so
    they are out of sync, this is most noticible on the sound when you
    listen to both at the same time.

    Is there anyway of fixing this time delay so they are in sync?

    I was think a good idea would be to make the cable to the faster box
    longer so the signal had to go futher, dunno how much cable I would need
    though, the delay is only about 1/5 of a second. I have some spare cable but
    I don't
    know what lenght to cut it too :O)


    TIA.
     
    Bazzer Smith, Sep 10, 2006
    #1
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  2. Bazzer Smith

    Bill Wright Guest

    Try 40,000km. Reduce it by 5,000km increments until it's right. It's OK to
    coil it up. Signal losses will be about 8,000dB if you use CT100 so you
    might need some compensating amplification.

    Bill
     
    Bill Wright, Sep 10, 2006
    #2
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  3. Bazzer Smith

    Bazzer Smith Guest

    Hmmm.. any chance of a quote on the job, I'll just use bog standard cable if
    it's cheaper :O)
    I would expect a bulk buyers discount though :O|

    And I want proper connectors too, not some twisted wires bodged job.
     
    Bazzer Smith, Sep 11, 2006
    #3
  4. Bazzer Smith

    Dr Zoidberg Guest

    Do you get good reception under your bridge?
     
    Dr Zoidberg, Sep 11, 2006
    #4
  5. Bazzer Smith

    Bill Wright Guest

    Come now. The man asked an honest question and got an honest answer.

    Bill
     
    Bill Wright, Sep 11, 2006
    #5
  6. Bazzer Smith

    Paul D.Smith Guest

    As you've realised, its not something that us poor mortals can achieve. You
    may be amused that DAB listeners have complained for sometime about the
    "time pips", which sound like a peel of bells as every DAB radio in the
    house goes off at a slightly different time, and all of them well behind any
    analogue radios. Of course digital radio off Freeview or Satellite goes off
    at a different time too!

    Of course DAB is of such high quality that surely people won't care about
    the fact that you can't listen around the house without all this bizarre
    "echo" affects, he said with his tongue firmly in his cheek!

    Paul DS
     
    Paul D.Smith, Sep 11, 2006
    #6
  7. |I have a freeview box and a freeview dongle (for my PC),
    |however they take different times to process the signals so
    |they are out of sync, this is most noticible on the sound when you
    |listen to both at the same time.
    |
    |Is there anyway of fixing this time delay so they are in sync?
    |
    |I was think a good idea would be to make the cable to the faster box
    |longer so the signal had to go futher, dunno how much cable I would need
    |though, the delay is only about 1/5 of a second. I have some spare cable but
    |I don't
    |know what lenght to cut it too :O)

    I have seen a similar thing done, a long time ago, by a *commercial*
    *professional* outfit, called IIRC Wigwam, in a long thin auditorium where
    there were several TV monitors a long way from platform, and they
    introduces a time delay for each ?video? stream to give lip sync with both
    the natural speed of sound time delay and the audio out of the speakers.

    Writing the above made me realise that I do not understand what they did,
    but it worked very well.

    Introducing time delays in audio and/or video streams is definitely
    possible, and might now be down to a reasonable price now.
     
    Dave Fawthrop, Sep 11, 2006
    #7
  8. Bazzer Smith

    Roger R Guest

    This won't be any help but.. did something like this many years ago.
    However the frequency was 70 MHz rather than baseband video.
    We used a couple of reels of cable, probably about 500m, and that gave
    sufficeint delay.

    Could TV delay line technology be of use?
    A TV delay line has a delay of one line = 0.06 ms so you would only need
    about 8000 of them ..or perhaps bigger capacitors ;-)

    Roger
     
    Roger R, Sep 11, 2006
    #8
  9. I beg to differ. Concerned with the low WAF of 5,000 tonnes of cable
    under the carpet, I coiled it on your advice, I might add, into a tidy
    bundle some billionth of a millimetre across, which I figured would fit
    out of sight behind the bookcase, when lo & behold, it promptly
    collapsed in on itself.

    Now I can't fit the last damned connector. Assuming you can suggest a
    suitable workaround to the termination issue, I'm still concerned the
    Hawking radiation will interfere with my reception. In your experience,
    is that likely to be a problem?
    That's another thing - it doesn't seem to matter how strong a signal I
    feed into it, nothing comes back out. It appears your calculations are
    off somewhat. I have to say I'm not at all happy with your advice.
     
    Michael Rozdoba, Sep 11, 2006
    #9
  10. IMHO Signal travels through cable at about a foot per nanosecond.

    So you can make up a delay line, but would it be practical?

    Good Luck

    Peter
     
    Peter Williams, Sep 11, 2006
    #10
  11. Bazzer Smith

    charles Guest


    we used to consider that video co-ax had a velocity factor of 0.8.
    Resulting in: 3 x 10e8 x 0.8 m/sec or 2.4 x 10e8m/sec or 2.4 x 10e2m/usec

    or 240m/usec or .24m/nsec. (nearer 9inches)
     
    charles, Sep 11, 2006
    #11
  12. Bazzer Smith

    Pyriform Guest

    Not if you use Mathew Orman's special FTL data transmission cable
    (sci.physics posts passim). The last I heard, he was claiming transmission
    speeds of several millions of times c, knocking Einstein into a cocked hat.
    The deluded fool even had a go at selling the prototype on ebay, with a
    starting price of $100,000. Sadly, there were no bids.
     
    Pyriform, Sep 11, 2006
    #12
  13. Bazzer Smith

    charles Guest

    but surely, to minimise the length of cable needed you need much slower
    transmission?
     
    charles, Sep 11, 2006
    #13
  14. Bazzer Smith

    Pyriform Guest

    Sadly slow speed transmission does not seem to be an area addressed by Mr
    Orman's cutting edge research. Using one of his cables, you'd probably get
    to see the programme before it had even left the aerial.

    More orthodox science may have the answer:

    http://news.zdnet.com/IBM+slows+light,+readies+it+for+networking/2100-9584_22-5928541.html
     
    Pyriform, Sep 11, 2006
    #14
  15. Bazzer Smith

    Bazzer Smith Guest


    This would do it probably!!
    http://delayplay.com/
     
    Bazzer Smith, Sep 11, 2006
    #15
  16. To match video to sound that's traveled just 13 metres, you'd need to
    store a whole frame (at 25fps). Doesn't seem that it could have predated
    high-density RAM chips. Mercury delay lines wouldn't be up to the job.
     
    Dave Farrance, Sep 11, 2006
    #16
  17. Bazzer Smith

    jasen Guest

    They probably used likely some sort of magnetic media,


    Bye.
    Jasen
     
    jasen, Sep 12, 2006
    #17
  18. Bazzer Smith

    CWatters Guest

    Which is faster.
     
    CWatters, Sep 12, 2006
    #18
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