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SWMLine Question

Discussion in 'DIRECTV Installation/MDU Discussion' started by compnurd, Oct 17, 2008.

  1. compnurd

    compnurd Hall Of Fame

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    I just picked up a PI21, 8-SWS and a SWM Line LNB for 50 bucks

    Question is, i knew there had to be distance requirements betweem the SWM-8's and the PS, does anything with the newer LNB set-ups have to have distance?
     
  2. Grentz

    Grentz New Member

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    Yes, minimum of 15ft between Power Inserter (PI-21 in your case) and the SWMLine LNB.
     
  3. compnurd

    compnurd Hall Of Fame

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    Ok Thats easy, does there have to be any distance between the PI and Splitter?
     
  4. David MacLeod

    David MacLeod New Member

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    no minimum I've seen, but there is a max posted for it. 21v I think is 100 feet.
     
  5. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I'd say as close as you can get it and still be indoors.
     
  6. Grentz

    Grentz New Member

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    Nope.

    The reason the PI has to be spaced from the SWM unit is to prevent over voltage. The splitter does not use any of the voltage, so not an issue.
     
  7. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "NOPE"
    It's for a poor RF match on the input of the PI.
    How much voltage drop are you expecting from 15' of coax anyway? :lol:
     
  8. David MacLeod

    David MacLeod New Member

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    HA, this conversation looks familiar :)
     
  9. Cmnore

    Cmnore Godfather

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    !Devil_lol :new_popco
     
  10. Grentz

    Grentz New Member

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    Hrm, must have missed that discussion. In the beginning everyone (including some reliable sources around here) was saying it was for voltage. Do you have any more details on it?

    Also 15' can amount to some power drop, I know with some Cat5/6 PIs they have minimums as well that are for voltage drop. The reason in that world is that the device can only compensate for such a difference in power, and the max threshold gets exceeded if it is very close.
     
  11. David MacLeod

    David MacLeod New Member

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  12. Grentz

    Grentz New Member

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    Ahh, thx for the link. I sometimes dont scan those large threads as often as I do the smaller threads ;) :lol:
     
  13. David MacLeod

    David MacLeod New Member

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    lol, I just saw the info on terminating I had missed :(
     
  14. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I was in a chat room where Earl brought in "Mr. DirecTV" and got to ask the question directly, as "the voltage story" was pure BS to me.
     
  15. Grentz

    Grentz New Member

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    Ahh, very nice. I believed you, just was curious if you had any more details :D
     
  16. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "Just" that it seems the 28/9 volt PI has a bad RF input match [DC block & choke on the DC feed] that 15' of coax can "move around a Smith chart" enough to get out of a reactive region that caused problems with "some" systems.
     
  17. Grentz

    Grentz New Member

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    Ok, that makes sense. Much more technical and of more sense than simply voltage drop as well ;)
     
  18. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Can I now go back to being "a blonde", please? :lol:
     
  19. Grentz

    Grentz New Member

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    As you wish :p
     
  20. bobnielsen

    bobnielsen Éminence grise

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    Bainbridge...
    You aren't going to get much of a match improvement from 15' either.

    15 ' of RG6 has an insertion loss at 2 GHz of 1.29 dB, which means that the return loss looking from the SWM toward the PI would increase by 2.58 dB. The PI must have a pretty poor match if that much of an improvement helps significantly.
     

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