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How can I receive Soarsat and 28.2 east with one Dish

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Comments

  • Closed Accounts Posts: 1,351 ✭✭✭Ronnie Raygun


    This allows the bar more tilt as there's more clearance within the mounting.

    Will help the furthest offset positions & I don't think anyone's reported adverse effects re. the more central lnbs.


  • Registered Users, Registered Users 2 Posts: 748 ✭✭✭RogerThis


    image33.png

    So there would be a gap between the holder and bar. Is this what is meant by putting the bar upside down? This will mean that it will be possible to tilt the bar west or east. Or should it be perfectly horizontal?


  • Closed Accounts Posts: 1,576 ✭✭✭excollier


    That's correct, but the east side of the bar should be as low as it will go.


  • Registered Users, Registered Users 2 Posts: 32,417 ✭✭✭✭watty


    It's because due South is highest elevation and zero skew. As you go east the elevation drops. As the dish is a mirror, the further East LNB (mounted on the West side of arm) then has to be higher to give less elevation!

    If the bar is at the correct angle then if the Elevation was correct for the location dish is pointed at the LNB on one side of arm is lower (more elevation) and on the other is higher. Only if the Dish was pointed due south would the bar be level.

    Of course the elevations are on a curve. But for only 20 degrees spacing you can approximate with a tangent to the curve (A straight line).

    The focus is on another curve that is much tighter to do with F/D of the dish, hence the bar is curved so that the ends are the same distance from centre of dish on Paraboloid axis (physically pointing to a point a bit above the centre of the dish as it's offset "cut" out of a larger symmetrical Paraboloid.

    Thus the LNBs for Ku are typically close to right angles on the bar. You can measure Ku "quality" and fine tweak bar slope with all Ku LNBFs at 90 degrees skew to bar. Then fine tune each LNBF if a particular satellite isn't H & V exactly orthogonal to orbit.

    Since the biggest market for these bars is in mainland Europe where the satellites are closer to due south, the "normal" arrangement of the bar only allows a small tilt. 28E is due south of Prague roughly, hence the standard arrangement can't tilt enough for Ireland (worst in the West).

    Also this is reason that in Ireland you should never buy Monoblock feeds. The spacing for 13E & 19E for example is different in Germany and West of Ireland. Also Monoblocks are hard to expand to more receivers (don't work with Multiswitches) and many receivers don't support cascaded switching so adding a 3rd or more LNB is hard. Also the F/D of a dish has to match the monoblock design or spacing is wrong. With separate LNBFs and a bar you get much better performance and flexibility.

    For more than 20 degrees you need a Wavefrontier T90 (the smaller one is rarely worth while unless you only what two very strong satellites that would work on 45cm in heavy rain that are 45 degrees apart). The Wavefrontier will do 45 degrees. More than 30 to 40 degrees consider multiple dishes. Motorised is really only suitable for single feed and "true" PVR would really need TWO motorised dishes if you wanted to watch 19E and record 28E. Multifeed with a large enough dish can drive probably 2000 tuners.


  • Registered Users, Registered Users 2 Posts: 748 ✭✭✭RogerThis


    So the 28.2e side is lower and the 9e side is higher. Is this correct?


  • Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    Other way round.


  • Registered Users, Registered Users 2 Posts: 32,417 ✭✭✭✭watty


    The dish is a Mirror.

    If it's a single feed the dish points more East and lower for 28E than 9E. 9E is more western than 28E, closer to South, thus dish points higher.

    Dish is a mirror!

    But if the dish is pointed AT 13E for example, then the LNBF for 9E (the more western and higher satellite) must be mounted to the East and lower due to laws of reflection. The more eastern and lower 28E LNBF then must be mounted to the West and higher.
    Triax dish (model unknown, but 90cm wide and 95cm tall)
    134102.png
    From Left to Right (West to East)
    28E

    19E-|-13E-9E

    The dish in this case is pointed at 16E and the bar has a new hole drilled

    A 80cm dish may need to be pointed at 13E or 9E. Note that while Saorsat needs largest dish in Ballycastle & Extreme South West, the different spot of Eurobird (weaker than Astra) on 28E means it's worst in South west and poor in Galway/Mayo where Saorsat is fine as Irish West coast is on edge. In contrast Eurobird is stronger in Ballycastle.

    So in most of NI you may point dish at 9E and offset 19 degrees for Freesat, also true for Irish Midlands to East Coast. May need 90cm to 110cm depending on location.
    In Tralee to Sligo you may need point dish at 13E to offset either side. May need 90cm
    Sligo to Donegal and Tralee to far South west you may need 110cm and point dish at 16E.
    From East of Shannon and east of Limerick City to East Coast it's possible an 80cm pointed at 9E with 28E offset will do as Astra & Eurobird are getting much stronger.

    Of course this all depends on actual service FEC, bandwidth, symbol rate, APSK settings and carrier EIRP used by RTE NL.


    Footprints:
    http://www.eutelsat.com/satellites/EUTELSAT-28A-coverage.html
    http://www.ses.com/4628782/astra-2a
    http://www.ses.com/4628614/astra-1n
    http://www.ses.com/4627942/astra-2b
    http://www.saortv.info/satellite-saorsat/saorsat-reception/ (Scroll down)


  • Registered Users Posts: 122 ✭✭oconnorw


    Hi,
    would a humax foxsat freesat hd satellite box work with saorsat in fta mode.
    Thanks


  • Registered Users, Registered Users 2 Posts: 32,417 ✭✭✭✭watty


    Yes, it does. You can add software to allow Diseqc in Freesat mode and have one channel list.

    Virtually any "Freesat HD" box in "FTA mode" works, but only ones with Diseqc allow Freesat and Saorsat reception, even then it's best to have the 28E on the Port1 of Multiswitch or Diseqc switch. A multiswitch is a better route than multiple Diseqc switches if you have a PVR or more than one receiver.


  • Registered Users Posts: 122 ✭✭oconnorw


    Watty,

    many thanks for the information. I have a humax forsat HD pvr. If I use a multiswitch can I also add software so as and have one channel list.? Where would i download the software.

    Many Thanks


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  • Closed Accounts Posts: 1,576 ✭✭✭excollier




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