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Thread: Curiosity about the markings on Multiswitches.

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    Default Curiosity about the markings on Multiswitches.

    Multiswitches show which connection is high and which is Low, why?
    Is this a hangover from the days when there were single polarity LNB's or did you buy an LNB voltage specific?
    Because unless I have missed something, you dont bother 'marking' the cable at the LNB end as to which is which or do you?
    I did see a diagram where 2 multiswitchs were 'cascaded' together so I could definately see the benefit of knowing which is which but that wouldnt happen too often would it?

    Now I understand why an STB uses both voltages to operate an LNB and why you need a Multiswitch for 3 or more STB's on a Dual outlet LNB (PayTV,not VAST) but today, why bother marking the terminals as they do as we generaly use a dual polarity LNB on each connection (Dual outlet LNB for convenience)

    Also the outlets are numbered, is it essential to attatch each STB in that order or is that too just a 'convenience'?
    Last edited by gordon_s1942; 22-02-12 at 06:51 PM.
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    Quote Originally Posted by gordon_s1942 View Post
    Multiswitches show which connection is high and which is Low, why?
    Is this a hangover from the days when there were single polarity LNB's or did you buy an LNB voltage specific?
    Because unless I have missed something, you dont bother 'marking' the cable at the LNB end as to which is which or do you?
    I did see a diagram where 2 multiswitchs were 'cascaded' together so I could definately see the benefit of knowing which is which but that wouldnt happen too often would it?

    Now I understand why an STB uses both voltages to operate an LNB and why you need a Multiswitch for 3 or more STB's on a Dual outlet LNB (PayTV,not VAST) but today, why bother marking the terminals as they do as we generaly use a dual polarity LNB on each connection (Dual outlet LNB for convenience)

    Also the outlets are numbered, is it essential to attatch each STB in that order or is that too just a 'convenience'?
    G'Day Cobber.
    There has been some controversy regarding this.
    My interpretation of the Data is:-
    Those markings are essentially for use with Universal Quad LNBs.
    The various codes are generated within the MS. (The codes from the STBs select which input, but do not generate the code for that input).
    Hi and Lo refer to the upper and lower (Ku) bands(22KHz, ON or OFF), while they are divided into H and V Polarity, (18 / 13 V).

    Many claim that they can use these inputs as four separate dishes or Multi LNBs on the one dish.
    I'm not set up to disprove that, so cannot comment, but am dubious.

    Kindest Regards, " The Druid ".

    Last edited by beer4life; 22-02-12 at 07:21 PM.

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    Thanks B4life, one thing I noticed looking at ads was the Hi and Lo can be on either side of the switch so there is no 'Industry Standard' there.
    Marking them makes it look tidier and clearer and does remove (hopefully) possible mistakes when connecting but I just wondered if way back when, they did it because of what was available.
    I had a look at one that has 6 IN and although I got a bit lost in the diagram, I followed why it was done.
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    Quote Originally Posted by gordon_s1942 View Post
    Thanks B4life, one thing I noticed looking at ads was the Hi and Lo can be on either side of the switch so there is no 'Industry Standard' there.
    Marking them makes it look tidier and clearer and does remove (hopefully) possible mistakes when connecting but I just wondered if way back when, they did it because of what was available.
    I had a look at one that has 6 IN and although I got a bit lost in the diagram, I followed why it was done.
    G'Day Gordon,
    This is the firm that holds the Patent Rights to the DiSEqC Protocol which is accepted as the Industry Standard.



    So whatever any one else postulates or interprets, they are in contempt.
    Very comprehensive information there if you take the time to wade through it.
    Kindest Regards, " The Druid ".


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    I think it's just to show the true capabilities of the multiswitch. They can be used with Universal Quad LNBs. However, I would image most are used in a dual LNB environment and exploit the 22 KHz (high) tone for additional switching.

    If you take the average Spaun 4 input multiswitch in a two dual LNB environment, you have the following:

    INPUT 1 (LNB A): V-LOW (13V, 0 KHz)
    INPUT 2 (LNB A): H-LOW (18V, 0 KHz)
    INPUT 3 (LNB B): V-HIGH (13V, 22 KHz)
    INPUT 4 (LNB B): H-HIGH (18V, 22 Khz)

    As you can see, this will allow 2 dual LNBs individually switched by a 22 KHz tone from the receiver. LNB A is selected when 0 KHz is sent, LNB B when 22 KHz is sent.

    An 8 input multiswitch in a 4 dual LNB environment is only slightly more complex:

    INPUT 1 (LNB A): V-LOW (13V, 0 KHz, Tone A)
    INPUT 2 (LNB A): H-LOW (18V, 0 KHz, Tone A)
    INPUT 3 (LNB B): V-HIGH (13V, 22 KHz, Tone A)
    INPUT 4 (LNB B): H-HIGH (18V, 22 Khz, Tone A)
    INPUT 5 (LNB C): V-LOW (13V, 0 KHz, Tone B)
    INPUT 6 (LNB C): H-LOW (18V, 0 KHz, Tone B)
    INPUT 7 (LNB D): V-HIGH (13V, 22 KHz, Tone B)
    INPUT 8 (LNB D): H-HIGH (18V, 22 Khz, Tone B)

    Generally, anything greater than 8 inputs uses the Diseqc 1..4 (Option A/B, Position A/B) commands.

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    Quote Originally Posted by manian View Post
    I think it's just to show the true capabilities of the multiswitch. They can be used with Universal Quad LNBs. However, I would image most are used in a dual LNB environment and exploit the 22 KHz (high) tone for additional switching.

    If you take the average Spaun 4 input multiswitch in a two dual LNB environment, you have the following:

    INPUT 1 (LNB A): V-LOW (13V, 0 KHz)
    INPUT 2 (LNB A): H-LOW (18V, 0 KHz)
    INPUT 3 (LNB B): V-HIGH (13V, 22 KHz)
    INPUT 4 (LNB B): H-HIGH (18V, 22 Khz)

    As you can see, this will allow 2 dual LNBs individually switched by a 22 KHz tone from the receiver. LNB A is selected when 0 KHz is sent, LNB B when 22 KHz is sent.

    An 8 input multiswitch in a 4 dual LNB environment is only slightly more complex:

    INPUT 1 (LNB A): V-LOW (13V, 0 KHz, Tone A)
    INPUT 2 (LNB A): H-LOW (18V, 0 KHz, Tone A)
    INPUT 3 (LNB B): V-HIGH (13V, 22 KHz, Tone A)
    INPUT 4 (LNB B): H-HIGH (18V, 22 Khz, Tone A)
    INPUT 5 (LNB C): V-LOW (13V, 0 KHz, Tone B)
    INPUT 6 (LNB C): H-LOW (18V, 0 KHz, Tone B)
    INPUT 7 (LNB D): V-HIGH (13V, 22 KHz, Tone B)
    INPUT 8 (LNB D): H-HIGH (18V, 22 Khz, Tone B)

    Generally, anything greater than 8 inputs uses the Diseqc 1..4 (Option A/B, Position A/B) commands.
    Many thanks, but that is beyond the original question?
    You've overlooked what Hi and Lo stand for or for that matter, Universal LNBs, which I believe I did explain.


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    Quote Originally Posted by gordon_s1942 View Post
    Multiswitches show which connection is high and which is Low, why?
    Is this a hangover from the days when there were single polarity LNB's or did you buy an LNB voltage specific?
    Because unless I have missed something, you dont bother 'marking' the cable at the LNB end as to which is which or do you?
    I did see a diagram where 2 multiswitchs were 'cascaded' together so I could definately see the benefit of knowing which is which but that wouldnt happen too often would it?

    Now I understand why an STB uses both voltages to operate an LNB and why you need a Multiswitch for 3 or more STB's on a Dual outlet LNB (PayTV,not VAST) but today, why bother marking the terminals as they do as we generaly use a dual polarity LNB on each connection (Dual outlet LNB for convenience)

    Also the outlets are numbered, is it essential to attatch each STB in that order or is that too just a 'convenience'?
    They show H and V because these devices arent always the first device after a dish in a satellite system, and H and V may have already been decided by a previous device (eg. a launch amplifier in an SMATV system). The same applies for any tones, etc.

    Numbering the outlets is done for convenience/future troubleshooting mainly, its even done on some splitters (both terrestrial and sat types).
    Last edited by nbound; 03-04-12 at 10:28 PM.

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