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Directv Over Fiber

Discussion in 'DIRECTV Installation/MDU Discussion' started by DSOUND, Aug 17, 2013.

  1. DSOUND

    DSOUND Cool Member

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    Has anyone ran Directv over fiber? The plan is to have a dish with 4 x 2.3Ghz splitters connected to a local SWM 16. The 2nd output of the splitters go to fiber TX/Rx. From there, it goes to another SWM16 to the SWM splitters to receivers. Thoughts?
     
  2. studechip

    studechip Godfather

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    Why?
     
  3. jsk

    jsk Icon

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    I would imagine that it would be for a longer cable run.
     
  4. kaminar

    kaminar Mentor

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    Anything is possible, but RG11 solves most longer runs.

    -=K=-
     
  5. peds48

    peds48 DIRECTV A-Team DBSTalk Club

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    how far you need to go to the second SWM16?
     
  6. carl6

    carl6 Moderator DBSTalk Club

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    The SWM16 needs to be able to pass both DC voltage (either 13V or 18V) as well as the presence or absence of a 22KHz tone/signal on each of the four coax lines from the dish. If you can find a suitable coax/fiber translator of some type that would preserve that signalling, the yes. Otherwise no. I doubt there is anything on the market today that does that.
     
  7. longrider

    longrider DIRECTV A-Team DBSTalk Club

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    I am just thinking out loud here, but as there will be a SWM16 at the dish connected by coax would that SWM be enough to power the LNB and lock the outputs? As the outputs would be locked the fiber connected SWM would not have to switch anything and could just receive the data.

    That said, I do agree that RG11 would be a much simpler solution for a long run
     
  8. carl6

    carl6 Moderator DBSTalk Club

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    Okay, good point. You don't need to get the dc voltage and tones from the second SWM to the LNB. But you do need to get the proper four "stacks" of channels from the LNB to the applicable inputs of the second switch. I'm not familiar enough with fiber options to know if there is a way to accomplish that. Perhaps someone else can comment.
     
  9. studechip

    studechip Godfather

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    Until the ts returns and tells us why he wants to use fiber, this is all speculation.
     
  10. HoTat2

    HoTat2 Hall Of Fame

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    I've heard of DBS over fiber as low loss feeders for an MDU install solution;

    In fact its not a new idea;
    For instance here ...

    http://www.dawnco.com/auto_links/pdf/FSS-95F12R.pdf

    But unless the TS wants to locate one of his SWiM-16s' quite a distance from the other, I don't see the reason for such an additional expense that RG-11 can't suffice.
     
  11. HoTat2

    HoTat2 Hall Of Fame

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    BTW;

    I've always been curious;

    When a digitally modulated CATV band of RF channels is sent over fiber like with say with FiOS TV (or the DBS RF frequency stack of 250-2150 MHz for this thread's topic) do the same modulation processes take place at light wave frequencies?

    That is, will the electrical-optical modulator create the same channelized band, but at light wave frequencies where each RF channel is now at a discrete light frequency and phase modulated as well?

    I mean, I'm familiar with amplitude modulating light beams for analog signaling, or pulsing them on and off to convey digital data. But phase modulating them as is commonly done at radio frequencies, which is actually a combination of an analog signal used to send digital data?

    Maybe, someone who knows the technical details of this process, can provide some insight. :)
     
  12. veryoldschool

    veryoldschool Lifetime Achiever DBSTalk Club

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    Maybe the easiest way to look at it is the "light" is merely the carrier being modulated by the RF.
    FiOS stacks several different lasers on the same fiber and each has its own bandwidth. [ie one 1550 nm laser may have 1 GHz bandwidth].
     
  13. DSOUND

    DSOUND Cool Member

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    Thanks everyone for the replies. We have to use fiber because it is over 3 city blocks away. A consultant designed the system, conduit installed, fiber ran and terminated with APC connectors. Directv installer connected the system and it does not work and he doesn't know what to do. He came out of the legacy ports to run down the fiber. As I understand it, the legacy ports are not to be used but I see posts where people are using them. I am trying to fix the problem and I think I know what the issue is. We are using the Dawnco fiber TX/RX units. I thought I might check this website to see if anyone else has done this as this website is a great resource. I will let everyone knows if my idea works.
     
  14. HoTat2

    HoTat2 Hall Of Fame

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    Yes, that's easy enough to say VOS, but I still have difficulty trying to visualize it. :)

    With FiOS TV for instance you have a traditional ~54-876 MHz digital CATV RF band modulating a single 1550 nm laser. But the RF band is actually comprised of individual "physical" channels in FDM each carrying time division stat-multiplexed data of "logical" channels in phase modulation,

    How is that time-frequency grid of channels actually impressed upon the single laser?
     
  15. slice1900

    slice1900 Well-Known Member

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    I assume it was/is not possible to install another dish in the location 3 blocks away? RG11 should be able to make a run of that distance if the signal was properly amplified before (and probably after) the run. It would need to be slope equalized as well. Though I have to say, if the system as designed doesn't work, I'd go back to the consultant who designed it and make him fix it. Hopefully something in his contract required that his design actually function!

    BTW, you say that the fiber is being fed from the legacy ports of the first SWM-16? This should be done using splitters - wideband satellite splitters, one port power passing in your case since you can't power the fiber. There is a significant (~10db I think?) signal loss from the legacy ports on the SWM16 which could possibly have something to do with your issues.
     
  16. DSOUND

    DSOUND Cool Member

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    Slice1900,
    From what I understand is that the Legacy outputs are 10DB down. That is why I think it will not work. I plan on using the splitters with passthru to see if it works as I stated in my original post. I was checking to see if anyone had done this before. I see lots of drawings on the Internet where they split the dish signal and go to two SWMs but nothing where one of the splits go across fiber. I plan on trying it tomorrow and will report back. Thanks everyone for the replies.
     
  17. Go Beavs

    Go Beavs Hall Of Fame

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    The legacy ports on the SWiM-16 still need a voltage and a tone/no tone so the module knows what stack to output. The fiber doesn't supply that which is probably why it doesn't work and why you need power passing splitters like Slice1900 recommended.
     
  18. Stuart Sweet

    Stuart Sweet The Shadow Knows!

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    I have done some fiber work with DIRECTV-- I have successfully used 4 fiber devices to transport the signal before it gets to the SWM. I have not tried using the legacy ports.
     
  19. HoTat2

    HoTat2 Hall Of Fame

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    Wow ... I just thought of that this morning as I woke up the computer ...duuh;

    Must of had brain-lock yesterday when I read the problem here. The legacy ports on a SWiM-16 are just like the outputs of an internal WB68 MS, needing voltage/voltage+tone control signals to generate anything on them.

    So yes, unless you are going to connect a polarity locker or something to the legacy ports first then from there to the fiber lines, you need to forget about using the legacy ports and just run the traditional 4 power pass splitter configuration for paralleling multi-switches.
     
  20. jlmtech

    jlmtech New Member

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    Yes, fiber is typical in many MDU, garden style, hi-rise, campus, etc. I have a lot of experience with it. actually did the refernce designs for MFH2 over fiber.
    Feel free to email or call me: jmcgowan@jlmtechmgmt.com, www.jlmtechmgmt.com, 908 330 9887.




    [SIZE=36pt]MFH2 Fiber Optic Distribution System[/SIZE]​





    [SIZE=22pt]Product Overview, Design Guidelines and Technical Description [/SIZE]​
    [SIZE=22pt]Rev. 2.1 Summary Version[/SIZE]​





    [SIZE=24pt]J. L. McGowan[/SIZE]


    [SIZE=16pt]November 12, 2007[/SIZE]
     

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