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Steel or Aluminium Dish?

  • 25-08-2011 10:21pm
    #1
    phelixoflaherty
    Registered Users, Registered Users 2 Posts: 1,475 ✭✭✭


    Was looking at this site......http://www.hm-sat-shop.de/en/antennen-triax/
    Is there any difference between an Alu. or steel dish with regards to reception...
    Alu. would be longer lasting?


Comments

  • #2
    Zardoz
    Registered Users, Registered Users 2 Posts: 6,015 ✭✭✭Zardoz


    phelixoflaherty wrote: »
    Was looking at this site......http://www.hm-sat-shop.de/en/antennen-triax/
    Is there any difference between an Alu. or steel dish with regards to reception...
    Alu. would be longer lasting?
    No real difference in reception .
    Aluminium dish is lighter ,so less wind load and will not rust .


  • #3
    darth_maul
    Registered Users, Registered Users 2 Posts: 317 ✭✭darth_maul


    Zardoz wrote: »
    Aluminium dish is lighter ,so less wind load and will not rust .

    Have to disagree with you here the lower weight of an Aluminium dish does not make it less of a wind loading, that has to do with size of dish (how much wind it traps) Actually Aluminium dishes can be more prone to wind damage as its not as strong as Steel (obviously if its a good bit thicker to compensate then it should be fine)

    If you really want a rust free dish then the Alcad or Triax Fibreglass dishes are they way to go. (if used with proper galvanised bracket), Actually fitted one of the Alcad ones today in a local RTE Radio station seems very sturdy, but mad money


  • #4
    cormac_byrne
    Registered Users, Registered Users 2 Posts: 487 ✭✭cormac_byrne


    Do the mesh type have much of an advantage re wind loading.

    I would image they should be better as some wind would pass through them and the holes would also be making them lighter.

    Also some of these are oval shaped, which I believe gives them a wider receive area, which makes them easier to aim. If that's so then they should also be less sensitive to being pushed out of alignment by heavy winds.

    I'm in Dublin with a 43cm mesh oval pointed at Astra 2 @ 28 degrees,
    it also picks up Astra at 19 degrees. I wouldn't have thought it possible for a single LNB to work over a span of 9 degrees, but it does.


  • #5
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    cormac_byrne wrote: »
    I wouldn't have thought it possible for a single LNB to work over a span of 9 degrees, but it does.

    I'm fairly sure even such a small dish needs some lnb offset, maybe it's a monoblock lnb?


  • #6
    moro_original
    Registered Users, Registered Users 2 Posts: 60 ✭✭moro_original


    Besides, the stainless steel construction makes the flux dispersal


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  • #7
    polyfusion
    Closed Accounts Posts: 679 ✭✭✭polyfusion


    cormac_byrne wrote: »
    ...
    I'm in Dublin with a 43cm mesh oval pointed at Astra 2 @ 28 degrees,
    it also picks up Astra at 19 degrees. I wouldn't have thought it possible for a single LNB to work over a span of 9 degrees, but it does.

    It doesn't, you're either mistaken, or have some freak reflection phenomenon going on there.

    Give us an example of a transponder from each satellite you think you are receiving, and what channels are on those transponders. Some transponders are common between 19.2E and 28.2E, which could account for the confusion.


  • #8
    12 element
    Registered Users, Registered Users 2 Posts: 719 ✭✭✭12 element


    cormac_byrne wrote: »
    Do the mesh type have much of an advantage re wind loading.

    I would image they should be better as some wind would pass through them and the holes would also be making them lighter.

    Also some of these are oval shaped, which I believe gives them a wider receive area, which makes them easier to aim. If that's so then they should also be less sensitive to being pushed out of alignment by heavy winds.

    I'm in Dublin with a 43cm mesh oval pointed at Astra 2 @ 28 degrees,
    it also picks up Astra at 19 degrees. I wouldn't have thought it possible for a single LNB to work over a span of 9 degrees, but it does.

    The holes in the dish make very little difference in terms of wind loading the reason they are there is to reduce the weight of the dish to make it cheaper to ship it around.

    Have you had your dish up long? I'd Imagine you might have problems with reception during heavy rain.

    Sky dishes are crap and are designed to be as cheap as possible.


  • #9
    cormac_byrne
    Registered Users, Registered Users 2 Posts: 487 ✭✭cormac_byrne


    polyfusion wrote: »
    It doesn't, you're either mistaken, or have some freak reflection phenomenon going on there.

    Give us an example of a transponder from each satellite you think you are receiving, and what channels are on those transponders. Some transponders are common between 19.2E and 28.2E, which could account for the confusion.

    I expect that you're right,
    the frequencies are almost the same for channel I picked to test.
    strangely the type and modulation differs.


    BBC3
    on the Astra 1H/1KR/1L/1M/Turksat (19.2E) list

    NIM A
    type DVB-S2
    Modulation 8PSK
    Orbital Position 192
    Frequency 10773000
    Symbolrate 22000000
    Polarization Horizontal
    Inversion Auto
    FEC Inner 2/3
    Pilot Auto
    Rolloff 0.35

    BBC3
    on the Astra 2A/2B/2D/Eurobird 1 (28.2E) list


    NIM A
    type DVB-S
    Modulation QPSK
    Orbital Position 282
    Frequency 10773250
    Symbolrate 22000000
    Polarization Horizontal
    Inversion Auto
    FEC Inner 5/6


  • #10
    polyfusion
    Closed Accounts Posts: 679 ✭✭✭polyfusion


    With that transponder pointed at 19.2E, you'd be getting 1 FTA and a couple of encrypted German HD channel(s).

    All part of the learning process. When I first started experimenting with my kit, I can remember one day swinging across the dish trying to find 30W, and was perplexed to see 19.2E come booming in. Took me a few moments to realise that the house was now in the way, and 19.2E was being bounced off the living room window into the LNB.


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