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Coax Aerial Connection Problems

Discussion in 'LCD & LED LCD TVs' started by stonieav, Jan 13, 2010.

  1. stonieav

    stonieav Member

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    Hi,

    I hope this is in the correct forum. I recently purchased a new Toshiba 19DV616DB for my daughters bedroom. Now I have tried the tv in my sons room and all appears fine. However in my daughters room the slightest movement of the aerial cable causes the signal to be lost. To determine where the problem lay I did the following;

    1. Tried new cable (cheapo).
    2. Installed a new wall plate.
    3. Tried another new cable (bit more expensive, classed as digital type but still just a coax).

    None of those seemed to make a difference. So I put it down to the TV, and got a replacement. Exact same thing happens again with the new TV with any of the cables I have. Took it back into the other room and again it is fine in there.

    So I disconnected the wall plate and double checked there was no issue with the connection. With the plate fixed back in the wall I am still finding that the slightest movement of the aerial cable causes the signal to be lost. The system is distributed via an 8 way amplifier in my loft with the feed coming from the RF2 output on my Sky Box, with the freeview signal being fed into the sky box also.

    Strange thing is when I remove the connection from the loft or from the wall plate next to nothing happens i.e the signal still holds but the slightest touch on the cable from the tv and its gone! Absolutely baffled. I am now thinking it can only be interference with the cable and some kind of field around it but I cannot think of anything that's causing it although the Sky Dish is literally through the wall from the tv set.

    Help anyone :lease:

    Thanks in advance.

    Brian.
  2. ProDave

    ProDave Member

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    What's the sky picture like on the tv (tune that into one of the analogue channels)

    I'll bet it's lousy, snowy or non existant.

    I'll also bet you have a cable break or short circuit somewhere and are not actually getting a signal to the tv from the amplifier. Instead the length of cable itself is acting as a very very poor aerial. Confirmed by your last paragraph.

    Check ALL the connections for a break or short, prime suspect being where that cable plugs into the distribution amp.

    Try also a different output from the distribution amplifier in case one output is fauly.

    Sort it out on analogue first (the sky signal if you have DSO'd) as that's much easier to see when you have a good or poor signal.
  3. stonieav

    stonieav Member

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    Thanks ProDave,

    The Sky picture is not brilliant but not really poor. No movement of the aerial affects the picture though. It appears its only affecting digital channels and possibly ones with a lower quality signal although there is no obvious signal meter on the TV. I am not sure if that is significant, digital only I mean. Looks like I will have to go and check the cable connection at both loft and sky box level to make sure the connections are sound. That said I would expect to experience that on other sets in the house. Sky picture is fine on all other sets so I am thinking it is likely to be at the connection at the amplifier as you say.

    I'll check it out and let you know.

    Thanks again.
  4. ProDave

    ProDave Member

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    If the sky picture is fine on the other sets but "not brilliant" on this one, you have your problem. Fix that so it's a good picture and the rest will fall into place.

    First swap the outputs of the distribution amp with another room. If it's still not brilliant, that rules out the amp.

    If so it must be a cable or connection problem. If no obvious shorts or bad connections, don't rule out damaged cable. Sharp kinks or bends can ruin a coax cable so if it wasn't installed carefully the whole cable run could be damaged. Also what about a nail through the cable somewhere?

    Are you using sky "tv link" devices to change channel from the remote rooms? if so does the one in this room work?
  5. stonieav

    stonieav Member

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    ProDave,

    I think I got to the bottom of it. Firstly I changed the output of the amplifier and it did not make a difference. So I went to the source of the system, the RF2 outout on the back of the Sky Box. The cable I was using was a male to female with a female to female adaptor to fit to the Sky Box. Fiddling with that increased the signal strength (found out how to see that info) on the one of the poor channels, Dave so I found an old cable I had m/f and put that in and Bingo!:clap:

    I had discounted that as a source of the problem because Sky was ok (not brilliant) but ok in the other rooms and the Toshiba TV worked fine in my sons room and his TV was ok also, Sky and Freeview. So I assumed the problem to be with the line to the bedroom in question. Terrestrial was not great in the other rooms now its great in them!

    At least the solution was a cheap one, I'll ignore the wall plate and cables I bought at the weekend, few quid. Funny you mentioned the magic eyes as I have a couple but have never installed them. The amplifier I bought a few weeks back was with a view to putting them in (passes the 12v DC signal) but I found out the wall plates need to be DC pas cable as well so that's my next purchase.

    Many thanks for you helpful posts and guiding me to a more thorough troubleshooting exercise. My daughter is a happy bunny now! :thumbsup:

    Brian.
  6. ProDave

    ProDave Member

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    Glad you got it sorted.

    Perhaps the room that gave trouble has a very slightly longer run of cable, enough to tip it over the edge given the weak signal feeding from the sky box due to the dodgy cable.

    If it's set up for sky distribution as you say, then only change the wall plates for non isolated ones where you will be using a sky tv link. If there are rooms where you don't watch sky or don't have a tv link, leave them as isolated outlet plates.
  7. stonieav

    stonieav Member

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    Cheers ProDave,

    I will take your advice on that.

    Thanks again.

    brian.

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