Another question about dish elevation

Discussion in 'DirecTV TiVo Powered PVRs & Receivers' started by prowler, Jun 24, 2009.

  1. prowler

    prowler New Member

    39
    0
    Mar 27, 2005
    Solsberry, IN

    Advertisements

    Just to be sure prior to digging any holes, I would like to confirm my understanding of dish elevation.

    The actual angle to the satellite is slightly higher than a line perpendicular to the face of the dish, right? The actual satellite feed to the dish is offset in order to avoid blockage by the LNB, right?

    I want to make 5ft pole with a fixed 43 degree arm - that I can carry around my wooded yard to search for the best dish location that is free from tree tops. With my 5ft pole plumb and with the Azimuth determined (205 degrees) I hope to select a viable location. Naturally, I will allow for years of tree growth.

    Am I on the right track here?
     
  2. JimSpence

    JimSpence Just hangin'

    30,919
    40
    Sep 19, 2001
    Binghamton, NY
    Just make sure that when you are wondering your property that the pole is plumb for the check.

    You might make it easy on yourself by taking a large piece of cardboard and draw the actual elevation angle on it. Drag that around with a level and sight that. Some also take a paper towel roll and paste it in that angle to sight through. Don't forget the compass for the azimuth reading. :)
     
  3. prowler

    prowler New Member

    39
    0
    Mar 27, 2005
    Solsberry, IN
    Just a note to say this novice found the answer to his question.

    "If your receiver says the elevation is 33 degrees, it means that the true satellite signal will be coming in at that angle. The the arm holding the LNB isn't pointing at that angle nor is the perpendicular face of the dish pointing at that angle. Instead, the perpendicular face of the dish will be over 20° LOWER in elevation. The elevation scale on the dish mounting bracket compensates for the degree offset."
     
  4. TyroneShoes

    TyroneShoes HD evangelist

    3,604
    0
    Sep 6, 2004
    That's a great explanation. The dishes typically used for DBS are offset dishes, meaning "offset" from perpendicular. A typical dish is parabolic in both dimensions. A multisat dish, which is usually offset, is parabolic in the vertical dimension and spherical in the horizontal dimension. This allows the geo sats to illuminate multiple focal points (multiple LNBs, one for each sat, typically combined into one or two physical enclosures).

    It is difficult to eyeball what an offset dish is pointed at, but if you draw an imaginary reflected angle from the LNBF to the center of the dish and back out, that sort of gives you an idea of the true look angle.
     

Share This Page

spam firewall

Advertisements