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Modulating with SWM and D12-300?

Discussion in 'DIRECTV General Discussion' started by jimstolz76, Dec 27, 2008.

  1. jimstolz76

    jimstolz76 Cool Member

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    Dec 27, 2008
    Hello all!

    Forgive me if this has been asked - I searched around a bit and didn't find anything.

    Just for the heck of it, I'm trying to modulate a signal on channel 3 onto the same RG-6 as my MBR D12-300. I've got a single LNB dish, 4 port multiswitch, and am using JVI 35SDX100 diplexers. (power passing on one leg, 40-2150 Mhz)

    I can get the modulated signal to work fine, but it seems to block the satellite signal to the D12. Any idea what would cause this?

    If I can't get it to work it's no big deal, but I'd like to understand what it is that isn't working. Attached is a little schematic of what I'm doing.

    Thanks!
     

    Attached Files:

  2. Grentz

    Grentz New Member

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    Jan 10, 2007
    You are trying to modulate the Xbox?

    Could be the diplexers are leaking onto the satellite line.
     
  3. bobnielsen

    bobnielsen Éminence grise

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    Bainbridge...
    Perhaps the diplexers won't pass the 2.3 MHz control signal which is sent from the receiver to the SWM.
     
  4. RobertE

    RobertE New Member

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    Jun 9, 2006
    Please clarify. Things just don't add up.

    Are you sure that you have a swm setup?
    A swm setup won't have a multiswitch, unless it's an external one.
    A single (dual) lnb isn't a swm system.
     
  5. jimstolz76

    jimstolz76 Cool Member

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    Dec 27, 2008
    Thanks for the replies. Yes, I'm modulating the Xbox. Like I said, just for the hell of it. :)

    I have a single LNB dish with one rg-6 going to a 4 port multiswitch outside. Inside I have an HR21 with a single rg-6 that feeds both tuners. I have a power injector on the line with the HR21. One more rg-6 goes to the D12-300.

    The 2.3 Mhz control signal would make sense to me. I'll have to look around for some different diplexers.

    FYI - I've worked in the LV world for the past 13 years (cable tech, security, MDU, now home theater/structured wiring/card access/cctv/distributed audio/video/control systems/programming/etc...), but haven't stayed up to date with sat technology as well as I should. I've left it up to the Directv people, but I'd really like to regain a working knowledge of these things. Forgive me if I leave out crucial info or don't understand an acronym... :)
     
  6. harsh

    harsh Beware the Attack Basset

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    Salem, OR
    I'm pretty sure that you'll find that all diplexers are going to whack everything below 950MHz.
     
  7. Grentz

    Grentz New Member

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    Jan 10, 2007
    Good ones leave a certain part of the lower spectrum untouched and do work with the SWM.

    I use Holland DPD2 Diplexers with my SWM setup and they work fine.

    http://www.techtoolsupply.com/index.asp?PageAction=VIEWPROD&ProdID=785
     
  8. harsh

    harsh Beware the Attack Basset

    21,192
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    Jun 14, 2003
    Salem, OR
  9. jimstolz76

    jimstolz76 Cool Member

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    Dec 27, 2008

    It looks like that specs out the same as the ones I'm using. I guess for $1.99 I can give them a shot, though. :)
     
  10. Grentz

    Grentz New Member

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    Jan 10, 2007
    BUT, if you look on the specs it only rejects 40-806 on the satellite side. So 2.3mhz should be unaffected as there is a large buffer zone between 2.3 and 40 even if the diplexer "leaks" a bit of interference and is not perfectly within spec.

    If you notice the STVC for example rejects 5-806 on the satellite band so with just a little "leakage" it could easily disrupt the 2.3mhz band and most likely does.


    I did a lot of research before purchasing and that seemed to be the main thing in common between ones that worked (rejected ~40-806) and ones that didnt (rejected ~5-806) with the SWM modules. Still it is no guarantee. The best guarantee seems to be to use the Channel Master set (1x http://www.solidsignal.com/prod_display.asp?prod=CM4002IFD and 1x http://www.solidsignal.com/prod_display.asp?PROD=CM4001IFD) but it is quite a bit more expensive.
     
  11. bakers12

    bakers12 ΔS > 0

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