Receiption Woes - Help Needed - Ghosting/Digital

Discussion in 'Satellite TV, Sky TV & FreeSat' started by tgl, Oct 19, 2005.

  1. tgl

    tgl
    Active Member

    Joined:
    Mar 2, 2005
    Messages:
    171
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    22
    Ratings:
    +4
    Hello,

    I am having great problems getting a clean (without ghosting) image on standard terrestrial TV which appears to have a knock-on effect on the Freeview image stability.

    The problem is that the line of site between my aerial and the transmitter is interupted by a big electicity pylon.

    If I point my aerial 5 degrees one side of the pylon I get perfect BBC1 and BBC2 Reception, and when I move the aerial 5 degrees the opposite side I get perfect ITV, C4 and C5 reception. There is no middle ground. Now the knock-on effect is that some channels are stable in Freeview and others become blocky. The channels that become blocky change depending on the direction of the aerial.

    I was then thinking of installing two aerials and combining the signals from both. They will point at the same transmitter but cover the good signals received either side of the pylon.

    The question is, does anyone know what I should use to combine the two aerial feeds with? I assume some kind of device that will synchronise the signals.

    Regards,

    TGL
    :lease:
     
  2. Chris Muriel

    Chris Muriel
    Well-known Member

    Joined:
    Jun 14, 2002
    Messages:
    7,286
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Manchester
    Ratings:
    +764
    Many splitters will actually work in reverse as combiners ; however I don't think this will solve your multipath/ghosting problem.
    2 aerials with dedicated feedlines and an antenna switch is one (slightly awkward) solution.
    Note that a log periodic aerial is more resistant to ghosting than a standard yagi antenna They do have lower gain than an equivalent sized yagi though.
    http://dastv.co.uk/DAS/Products/ViewProduct.aspx?ProductID=287&RangeNo=1
    LP45 is an example.
    This would be worth experimenting with.

    Chris Muriel, Manchester
     
  3. Nick_UK

    Nick_UK
    Banned

    Joined:
    Nov 13, 2004
    Messages:
    9,748
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    103
    Ratings:
    +272
    If moving the aerial only 5 degrees has an effect, then moving the aerial itself may also help. Altering the height of the aerial could have an effect, as could altering the slope of the aerial (tilt). Also, structures such as this can also affect the polarization of he signals, so rotating the aerial polarisation could help too.
     
  4. Chris Muriel

    Chris Muriel
    Well-known Member

    Joined:
    Jun 14, 2002
    Messages:
    7,286
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Manchester
    Ratings:
    +764
    Great point about possible polarisation shift - which I should have thought of myself :-(

    Chris Muriel, Manchester
     
  5. tgl

    tgl
    Active Member

    Joined:
    Mar 2, 2005
    Messages:
    171
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    22
    Ratings:
    +4
    Thanks for your prompt responses. I will have a go this weekend to see how changing the aerial polorisation will help.

    I live in a semi-detached house, so aerial re-locating will be difficult, although I guess pushing it into the loft might make the difference.

    Regards,

    TGL
     

Share This Page

Loading...