Is there a solution to this problem?

Discussion in 'DirecTV TiVo Powered PVRs & Receivers' started by lark, Feb 11, 2005.

  1. lark

    lark New Member

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    Nov 5, 2002
    The situation: I have two coax cables going from my roof to behind my television. It will be extremely difficult and expensive to add another.

    My multiswitch is on my roof, as is my OTA antenna. I use a diplexer on the roof to combine the antenna lead and one of the outputs from the multiswitch into one of the cables heading to my tv, where I use another diplexer to strip the signal -- I send the sat to my directivo and the antenna to my antenna input. I use the other cable to go directly from the second tuner on my directivo to another output on the multiswitch. Pretty standard setup. No problems.

    The problem: Despite trying everything, I simply cannot get CBS HD over the air. I do not live in an O&O, so it is not availble to me via directv.

    The potential solution: As it turns out, I get my high speed internet from my cable company, and it includes free basic cable, which includes the networks in HD. My television, happily, has a QAM tuner for unscrambled cable channels. So I could get CBS HD this way, if only I could deliver the basic cable from my roof to my tv.

    So that's the problem -- two coax cables to tv and a need to get two satellite signals, and OTA antenna signal, and cable to my television. Of course, I can only watch one thing at a time, so if there were some way to switch one of the coaxs between cable and satellite that might work. But I'd have to be able to do it remotely. Any other solutions? Is there any such thing as a diplexer for cable/satellite? (I'm assuming that if I understood the technology this would be a really really stupid question, but who knows.)
     
  2. TyroneShoes

    TyroneShoes HD evangelist

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    Sep 6, 2004
    A little confusing.

    It would seem that you should be able to split at the inside outlet that feeds your cable modem, and connect that to your set (assuming that the QAM input is separate from the NTSC/NTSC input, as it is on my Sony) which would bypass the sat cables altogether. Or.....

    Most cable systems use 500-750 MHz for the digital cable, some use up to 1 GHz. Sat signals are converted to L-band (typically 950-1450) at the LNB. Theoretically, you could diplex those signals on the other cable, providing you can find diplexing equipment that splits at 750-950, or at least splits above the frequency used by CBS QAM and below 950. It would have to pass DC from the dish to the receiver, and block DC on the cable ports. My best guess is that regular diplexing equipment should be able to do this. Find a good installer, and propose this to them. You may get lucky. The only remaining problem is you won't be able to Tivo CBS HD.
     
  3. lark

    lark New Member

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    Nov 5, 2002
    Yes, I can do this. The problem is the that the outlet that feeds my cable modem is about 50 feet away from the tv. I did do this, though, to confirm that it would work, but my wife won't go for 50 feet of cable lying across the house!

    Maybe I'll just try a regular old diplexer and see what happens, although I don't want to mess up any of my equipment.
     
  4. dswallow

    dswallow Save the Moderatоr TCF Club

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    Use a pair of diplexers on the other satellite cable to diplex the cable signal in with it, just like you're doing with the antenna signal over the other.
     
  5. lark

    lark New Member

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    Nov 5, 2002
    Doug -- thanks; just regular old diplexers with a single current pass through on the satellite side; same ones I'd use for the antenna?
     
  6. RMSko

    RMSko Active Member

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    Westfield,...
    For CBSHD OTA, have you tried using an amplifier? I couldn't get some OTA channels either, but once I added an amlifier, they came in perfectly.
     
  7. dswallow

    dswallow Save the Moderatоr TCF Club

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    Yep, in most cases they'd work just fine.

    You may need to use some that have a lower threshold for the cable/antenna side, though, if the cable receiver needs 2-way communication. The Spaun SEW121F (http://www.spaun.com/tech/SEW121F.pdf) (formerly SEW120F) specs show 5MHz-862MHz; most others will start around 40MHz.

    The Spaun diplexer isn't cheap, though -- typically around $40: http://www.twacomm.com/Catalog/Model_SEW121F.htm
     
  8. lark

    lark New Member

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    Nov 5, 2002
    Diplexers did the trick. Thanks everyone.
     
  9. oldskoolboarder

    oldskoolboarder New Member

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    Jul 8, 2003
    Bay Area, CA
    My triple LNB output comes into my wiring panel where my DSL is connected. The wall is stuffed such that I can't run any more cables w/o tearing up drywall. I want to put a cable modem near/in the panel.

    1) Can I use diplexors on either end of one of the D* sat cables and MUX a cablem modem signal on it?

    2) Anyone try it?

    3) Cheap diplexor source that will work?

    Thanks. I'm done w/ SBC DSL, tired of rebooting my modem several times a week. :mad:
     
  10. dswallow

    dswallow Save the Moderatоr TCF Club

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    Yes you can but you usually do need to ensure the diplexers you use have a low pass capability for the antenna cable down around 5 or 10MHz or less. You probably won't find most cheap diplexers go that low by spec, but in practice they might do OK. But there are some brands that do get tested and certified down that low -- stick to those.
     

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