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Need to hook up 19 boxes to a single LNB SWiM dish.

Discussion in 'DIRECTV Installation/MDU Discussion' started by TauCephei, Jan 9, 2012.

  1. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    It was the SWM8s that didn't. "they fixed it" with the newer 16s & 32s.

    "And" there are now four "legacy" ports too.
     
  2. P Smith

    P Smith Mr. FixAnything

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    When I did ask ... yeah, yeah ... 95W still there, but 72.5W gone - no more Flex#2 port using.
     
  3. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Earl deserves "his own".
     
  4. P Smith

    P Smith Mr. FixAnything

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    I'm not for myself - for all ppl here who will look at diagrams.
     
  5. DarkLogix

    DarkLogix Godfather

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    From my reading it looks that the dishes for 95 have 2 coax coming from them, so it looked that to use 95 and 72.5 you'd have to use a multiswitch to (assuming that there's 2 voltages or something going on)

    in short if you were to get a 95 couldn't you use both Flex 1 and 2 for the 1 dish?
     
  6. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    While this is wandering a bit too far, the 95 SAT is linear polarization and uses only one coax.
     
  7. DarkLogix

    DarkLogix Godfather

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    ok I guess the 2nd coax was ether in error or for some other reason, I did have a fishy feeling about it

    could they one day have a new sat in a new position that could use flex#2?

    /last ot question
     
  8. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    They could, but it's doubtful they will.
     
  9. DarkLogix

    DarkLogix Godfather

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    Ya I was just arguing the point that P smith made about no more flex#2 use
    /end OT
     
  10. HoTat2

    HoTat2 Hall Of Fame

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    No the 95W "World Direct" dish in SD installations actually should have three lines. Two for a standard 12.2-12.7 Ghz 101 LNB and one for a 95W 11.7-12.2 Ghz linear LNB, both mounted at the focal point of the dish.

    Its just that in HD installs when used in conjunction with a SlimLine 3/5 dish it is customary to not even bother running any lines for the 101 LNB since its not used.

    EDIT: My bad, for a standard installation there actually should be "three" cables coming from a World Direct dish for an SD install as corrected above due to two cables for the 101 LNB.
     
  11. HoTat2

    HoTat2 Hall Of Fame

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    Although for some strange reason, I read in a D* tech bulletin about the SWiM-16 awhile ago, the exact edition I can't remember at the moment. That cascading two of them this way was not yet recommended. :confused:

    Never could figure out why, or if that advisory was ever since officially rescinded.
     
  12. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Yes there was "some story" about not doing this, but it works and does look to be "by design".
    Some of the tech bulletins make me wonder.
    One of these was about the HR20-100 & DECA.
    Engineering had us in the test group use a splitter behind the DECA so it would power the DECA off the SAT #2.
    Then a "tech bulletin" came out moving the splitter to in front of the DECA, connecting the DECA to SAT $2, which also required a BSF on SAT #1.
    This really doesn't make any sense as it requires a BSF that wasn't needed before, and doesn't change anything.

    [​IMG]
    [​IMG]
     
  13. HoTat2

    HoTat2 Hall Of Fame

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    BTW, happened to stumble across the particular "Technical Bulletin with points against cascading SWiM-16s highlighted. As to why is anyones guess.

    Sorry for posting it to this thread somewhat belatedly :D

    Issue 5 2011 – 4.25.11

     
  14. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "Any yet" it's been done for over a year without any problems, Earl is doing it, and is done in MDU systems. :shrug:

    These are the same folks who took this:
    [​IMG]

    And issued a bulletin turning it into this:
    [​IMG]

    Now, I'll ask ANYONE what the difference is other than requiring a BSF that the first didn't. :nono:
     
  15. DarkLogix

    DarkLogix Godfather

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    That sounds more like they're saying not to parallel SWM16's

    it just sounds like they're using a parallel setup and saying cascade, because there would be no need for power passing splitters if cascased but there would be if paralleled
     
  16. HoTat2

    HoTat2 Hall Of Fame

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    No it seems pretty clear they're saying quite the opposite;

    Note the highlighted points again:

    · Utilize a power passing splitter if using more than one SWiM 16. Do not cascade the SWiM 16 due to high signal loss.

    · If you need to use 2 SWiM 16 Multi-Switches, power passing splitters should be used between the SLIMLINE LNB and the 2 SWiM 16 Multi-Switches. When using splitters, you need to make sure the same polarity is used from each splitter to the corresponding satellite in on the SWiM 16 Multi-Switch. For example: the same splitter must feed the 18V sat 99/101 sat in port.

    · Use of the legacy ports for SWiM or non SWiM capable receivers on the SWiM 16 is not recommended at this time.


    This clearly says that when two SWiM-16s are needed, paralleling is to be used and not cascading.

    It appears when this TB was written for some reason they didn't (yet anyway) recommend use of the legacy ports due to a perceived "high (internal) signal loss" between the 4-6 satellite inputs and the legacy port outputs.
     
  17. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    This brings up the question [that I don't have the answer for] of where's the AGC in the SWiM?

    A) If it's on the output, then the legacy [or cascade as they're called on the SWiM-32] ports are low, since these have been measured with -30 dBm input to have -40 dBm output.
    This would mean as the input drops even further, that the legacy ports would be "in the dirt" fairly quickly.
    SWiM reaches full gain by -45 dBm to maintain the -30 dBm output of the SWiM.

    B) If it's on the input, then the legacy/cascade ports are also regulated by the AGC, and with -40 dBm, the second SWiM adds the 10 dB through its AGC to the SWiM output for it to have -30 dBm, with have another 5 dB for any extra cable loss.

    With A, those that have been running them cascaded, should have been seeing 771a errors with moderate rain, on the receivers connected to the second SWiM.

    With B, both SWiMs have the same range of output power, as the first SWiM regulates the power for rainfade control, while the second compensates for the loss of the legacy/cascade ports.

    Now anyone that has a SWiM-16 and a meter that measures power, let me know and I'll give you some tests to run to see where the AGC is.
     

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