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Will this help stop sound dropouts and picture breakups?

Discussion in 'Satellite TV, Sky TV & FreeSat' started by 9761, Jun 8, 2005.

  1. 9761

    9761
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  2. Nick_UK

    Nick_UK
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    None of the links work for me :confused:

    If you are getting sound and picture breakups, it's probably interference causing it. You need a good rooftop (not loft) aerial connected to the TV via good-quality foil-screened co-axial cable. The older type of open-weave screened cable will let interference through.
     
  3. 9761

    9761
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    Well my aerial is on the roof and uses brown coax cable :( and it goes into the loft where it meets a booster then from there it use WF100 cable that goes into my room.

    I know its not all of the cable has been replaced but I dont want to get onto the roof and start messing with cable and dont really want to spend loads getting a aerial installer to fit it.

    Thanks
     
  4. 9761

    9761
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    Links work now :)
     
  5. Nick_UK

    Nick_UK
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    It's unlikley that any of the devices will work, especially the last one. Unfortunately the most important piece of cable (the one from your aerial to the amplifier) is probably still unscreened, and aerial amplifiers will amplify both wanted and unwanted signals (interference). Another problem is that many cheap aerial amplifiers will pick-up mains-borne interference, and make the problem worse.

    The interference could be caused by ignition interference picked up from the road (especially if you live on a busy street), or mains-borne interference from your house and your neighbours. In both cases you need an aerial which picks up more of the wanted signal, which might even remove the need for a booster if it was big enough. Only an experienced aerial contractor could advise what you need, after examining what you already have.
     
  6. 9761

    9761
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    Ok thanks

    Is there any good amplifers that wont pick-up mains-borne interference?

    When I get me self some more money I will see if I can get one of these aerial installer people to come and have a look.
     
  7. Nick_UK

    Nick_UK
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    Most reputable makes are OK. Avoid the cheap ones sold in DIY stores. You could try bypassing the amp, and see what effect that has.
     
  8. 9761

    9761
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    Ive tried bypassing the amp and the picture is rubbish just about make out some colour on my screen.
     
  9. Nick_UK

    Nick_UK
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    Then you really do need a new aerial ! :)

    You'll never get a good Freeview picture if your terrestrial (analogue) signal is that bad. I'm surprised it works at all.
     
  10. 9761

    9761
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    Well it looks like I will be saving now and getting a quote of one of those aerial installers. I did see somewhere selling a 75element aerial would it be better if I brought that and get an installer to fit it?
     
  11. bert2

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    I'm having the same problem and would like you all to continue this thread to a conclusion, if possible.

    I've just bought a 36" WS set and, to inprove the analogue signal had an installer fit a large wide band aerial with masthead amp. As I indicated an interest in freeview he lent me a box.

    Analogue is fine, with a variable signal attenuator as the signal was too strong, but I have the picture break up and sound screeches on Freeview on all channels except BBC1. I can vary the signal strength and quality up to 100% but at this the analogue picture has banding on it sometimes. Setting the attenuator to get the best analogue picture results in a Freeview signal strengh on BBC1 of 85% and a similar quality figure. The quality dips when the breakup and sound screech happens.

    This thread made me realise that the installer had not replaced the cable from the ariel to the wall so I will be talking to him about this. I discussed this when he did the install but he said it would not effect anything.

    I will let you know what happens.
     
  12. Nick_UK

    Nick_UK
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    Attenuators are best fitted before the amp, not after. The aerial could be overloading the amp.
     
  13. bert2

    bert2
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    I'm confused about the attenuator, and the amp.

    The amp consists of a unit on the ariel and a power supply in the viewing room. The ariel lead plugs into a socket marked 'AMP' and the output is to the TV. There is no lead supplying power to the ariel mounted unit. I expected a power lead up to the ariel unit so, if the unit on the ariel is powered, the supply is up the ariel lead. Seems strange to me. How does it work?

    If the attenuator should be before the amp does that mean it should be on the ariel side of the amp unit on the ariel, in which case my variable, and unsealed, unit is useless, or are you saying it should be before the power supply?
     
  14. Nick_UK

    Nick_UK
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    Hmmm.... if the amp is actually on the aerial, there isn't much you can do (apart from getting the installer back to fix the problem). Some amps are fitted in the loft - I thought you might have one of those.

    The power for the amp does go up the co-axial cable from the power unit. That's a fairly common method of getting the power up to the amplifier.
     
  15. bert2

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    Thanks Nick, I thought that must be it. Makes a nonsence of not having signal and power cables near each other but I suppose the low voltage feed is OK.
     
  16. HarryAlffa

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    Are you in a poor (analogue) reception area?

    My parents house had an outside ariel with a very poor analogue signal and subsequently flaky Freeview reception. I experimented and found that a crappy old outside ariel with a brand new piece of cable in the loft gave a near perfect picture. The old brown coax was severely corroded - the copper wire was green and crumbling!

    See if you can't get any old ariel, but with perfect cabling, plugged into the booster in the loft and see if that is any better. It might mean that you will avoid the expense of an installer and can be perfectly happy with an ariel (even a DIY one) and sensible cabling sitting in the loft; which will last for ever as it's out of the wind and rain! That's what I've installed in my parents house. Cheap and perfect!
     
  17. Nick_UK

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    Good cabling is essential for Freeview. People tolerated white dots on their pictures on analogue caused by interference, but unfortunately the same sort of interference on a digital system causes sound pops and picture pixellation. Because digital TV is broadcast with a much lower power than analogue TV, it only aggrevates the problem. Old cable used on analogue TV doesn't have the extra metal foil screening that the newer cables have.
     

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