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Thread: Multi-satellite installations

  1. #1
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    Lightbulb Multi-satellite installations

    The elements described above are common to all satellite dishes, whether you go for a single, or a multi-satellite set-up. If you want to watch more than one satellite, you have some extra elements, depending on whether you go for a motorized or a multi-LNB installation.
    • If you go for a motorized dish, you only need one LNB head which has the frequency span to cover all used on 'your' satellites. The motor is attached to the dish, and should be goverened by the receiver inside, so that when you choose a channel, the dish will automatically move to the correct position in the sky. Thus, the receiver must be able to talk to the motor. Motors are mostly of two kinds, the older 'actuator' motors, and the newer 'DiSEqC' standard. Make sure that the receiver is able to run the motor you have (otherwise, you may need a separate 'interface' between the motor and the receiver to make the connection). Motorized dishes are more complex to install, so you would certainly want a professional to set it up.
    • If you instead go for a fixed-dish multi-head system, you also have to consider the size of the dish. Each of the heads will be pointed at (or, actually, directly away from) its own satellite, thus at a slight angle from each other and not at the centre of the dish. That means it cannot receive signals reflected from the total area of the dish. So you must compensate by installing a slightly larger dish than you would with a single head, to let even the most off-centre head receive enough signals for good reception.
      • Each head will be pointed away from each other by as many degrees as the satellites are apart in the sky. The head can use signals reflected from within a circle centred around the focus of the LNB. So if the LNB points to a spot five cm off the centre of an 80 cm dish, then its reception is that of a 70 cm dish (5 cm radius=10 cm diameter). If you need a 70cm dish for good reception from each satellite, you will have to install one of 80cm to cover both. Commonly, multi-satellite dishes have a maximum span of about 20 degrees from the western- to the eastern-most satellite it can catch (the maximum angle of the LNBs to the dish), i.e. from Astra 1 to Thor or from Astra 2 to Hotbird.
    • When you have two or more LNBs sitting in the dish, you could of course run one cable from each LNB through your wall in to the receiver. It is rather more practical, however, to merge the signals outside, so that they all run down one cable inside, and the receiver inside then is able to switch to the LNB it wants for each particular channel. The most common way of doing this is with a piece of hardware with the unreadable acronym 'DiSEqC' switch (Digital Satellite Equipment Controller, I think - I tend to pronounce it 'disec'). It is in fact a European standard for how to handle multiple equipment, so what you want is, one, the piece of hardware outside that joins the cables from the LNBs into one (the switch), and two, that your receiver inside has the software to control the switch and pick the right LNB. However, the DiSEqC standard has gone through several generation, and how much the equipment can do, depends on which version of DiSEqC it supports:
      • Version 1.0 can handle up to four different LNBs, in some early versions only two.
      • 1.1 can handle up to 16 different LNB, more than enough for most of Europe. That is therefore what you should look for.
      • 1.2 is different, it is designed for motorized dishes (we mentioned it above), and can control up to 30 predefined positions.
      • There is also a version 2.0, this is not much in use yet.
    The choices you have to make, therefore, mostly concern the equipment outdoors: a single or multi-satellite setup? if the latter, fixed-dish with many heads or motorized with one? if the former, DiSEqC and what version? If the latter, what kind of motor?

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    Thumbs up Re: Multi-satellite installations

    Hi All, here is an example of multi LNBs mounts.:D
    Kindest Regards,Bill.
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    Talking Re: Multi-satellite installations

    Hi All,

    And as "MainFrame" has said, you can save yourself a lot of hassles if you use one of these at the dish, with a single Co-Ax to the STB. As mentioned, you use the DiSEqC control in the STB to switch between SATs.:cool:
    Kindest Regards, Bill.
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    Re: Multi-satellite installations

    Hi!

    I would like to know if there is a possibility to connect two receivers to the same DiSEqC (4 LNB's) using a tee branch and having both on, and tuned to different channels on the same satellite or two different channels on different satellites.
    Knowing that it works only with the two receivers tuned to the same channel. (same channel on the same satellite).

    Thank you in advance.
    Judos.

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    Thumbs up Re: Multi-satellite installations

    Quote Originally Posted by judos
    Hi!

    I would like to know if there is a possibility to connect two receivers to the same DiSEqC (4 LNB's) using a tee branch and having both on, and tuned to different channels on the same satellite or two different channels on different satellites.
    Knowing that it works only with the two receivers tuned to the same channel. (same channel on the same satellite).

    Thank you in advance.
    Judos.
    -----------------------------------------------------------
    Hi "judos",
    First I must correct your assumption that two STBs can only be tuned to the same frequency. You must have a master STB that controls H or V polarity, then either can tune the same polarity across the BLOCK of frequencies that the LNB can download.
    Nothing is impossible. The first thing that you must understand is that the Standard or Universal LNBs(Low Noise Blocks) downloads a block of frequencies that the STB tunes across. Either H or V polarity. There is a specialised "OrthoMode" LNB that has both H & V outlets.(two downleads). These are used in Motels etc where many STBs can operate independently over all channels, both H & V, from one dish. with a complex system of DisEqC switching, it would be possible to do what you suggest. I refer you to "Eutelsat" the originators and patent holders of this system. For 4 Sats you will have 8 downleads, and then a real spider web.

    http://www.eutelsat.com/fr/satellite...r-receiver.pdf

    Anything can be done, but the cost may be a deterent. I hope that this puts you on the right track for further research.

    Kindest Regards, Bill.B-)

  6. #6

    Re: Multi-satellite installations

    These guys have a good article on a home made setup

    http://www.thedropzone.co.nz/satellitehome.htm


    They receive Optus b1 b3 and c1 via a home made mounting lnb kit back to Progdvb

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    VIP Member daBimbo's Avatar
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    Re: Multi-satellite installations

    Hello. I need help installing my new Dish.

    Today I bought a 90cm Dich, a second LNB, a DiSEqC switch. I installed the dish and put up only on LBN to find Astra. I got the picture from the first time. The Elevation is set to 37.5° just like it should be for my location. the signal quality was around 80% for the most channels. I think I should get more, up to 90% should I get, I think. The problem is after I put up the spacer ( I call it spacer ) on which I can have two LNB's ( one on 19.2° and the other on 13° ) then Hotbird had no Signal. Well only hte JSC channels had signal of about 35%.

    The first quesiton is about positioning the LNB's on this spacer. Here is an attachment of it. Could you please mark the places where I should put the LNB for Astra and where the one for Hotbird ? ? ? Which one whouls be the main one ? ? ?

    And the second question is . . . is it possible that I have to move my dish a bit further, well more to west and more to east. I didnt' try that much cos I started to put it up a bit too late and I would still play around it in the night.

    I have an analogue reciever which doesn't show the signal quality, so I can only say wether the program is good or not, and now it's perfect. I only have Skystar 2 and ProgDVB for the signal quality check. Is there maybe some kinda program that that can show the quality of the signal live, I mean,while you're moving the dish the signal changes ( horizontal and vertical )

    Thanks.
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