OTA Pre Amp Through Diplexer ?

Discussion in 'DirecTV TiVo Powered PVRs & Receivers' started by Onazuka, Sep 9, 2007.

  1. Onazuka

    Onazuka New Member

    Sep 22, 2001


    I have a Winegard Square Shooter OTA antenna that came with a pre amp. One part of the pre amp is in the attic, the other part in the basement. I then take the OTA and put it through a diplexer, run it up to my family room (50+ feet) and through another diplexer to my HR10-250.

    I recently had my HR10-250 in the basement and connected the OTA up right after the pre amp and the OTA signal strength was much better than up in my family room. I'm having some OTA signal strength problems so I'm looking for any way to improve it. I'm guessing that if I put the pre amp up in the family room the OTA signal would be better up there.

    Can I go through the diplexers and put the pre amp up in my family room or do I have to have yet another dedicated cable run up to my family room in order to have the prea mp there ?
  2. spankspank

    spankspank Active Member

    Nov 7, 2000
    To answer an antenna question properly we need to know the antenna model AND distance from the broadcast towers. antennaweb.org will tell you this. This is the only way to know how much signal (in DB) one might expect from your antenna.

    As you may know the HR10-250 really likes a strong signal, but not too high. I think you have ruled out the too high because of your basement test.

    Diplexers do rob signal from you. How much depends on their quality. I think the garden variety suck. I have one set that I use with success. The rest I should ebay.

    I have long cable runs (over 100'). 50 ft of cable (RG6 right?) takes a bit of signal, but it shouldn't be that much. Is it possible that your 50ft cable run is causing you trouble because of shorted connectors?

    It sounds like you are wanting to move the DC power supply brick of the pre-amp closer to the DVR. I don't know why distance away would effect signal DB if the supplied voltage had an un-split path to the pre-amp.

    In fact, your idea to move the DC power brick behind the diplexers might block the path of required power. (Do diplexers usually pass DC?)
  3. mkinn

    mkinn New Member

    May 15, 2002
    Most diplexers will short out the DC power supply and you'll have to buy another. Cut and strip an inch off both ends of a spare short coax jumper. Tie them together so you can still connect and use a DC voltmeter ($15.00 at Radio Shack) to measure the DC volts before and IMMEDIATELY as you hook up the diplexer. If the voltage drops to 0 VDC, disconnect it immediately. If not, it passes DC and you're ok. Test both diplexers, if they're not the same make.
    Put the preamp right at the antenna for the best S/N. Multipath is a bigger problem than signal strength, though. If your unit has a signal quality meter, use that to aim several channels for a good compromise. If the meter drops out, you've got multipath problems.
  4. Onazuka

    Onazuka New Member

    Sep 22, 2001
    Thanks. I'll try quickly measuring the DC voltage.

    I'm not going to start trying to chase down multipath problems again since I see a stronger signal in my basement than family room.

    From what I can tell the coax run is OK since I have 2 runs (for my dual tuners) and have tried both with the diplexer.

    Duh, I guess I can try just unpluging the diplexers and using the coax for just the OTA signal and moving the pre amp up to the family room as a test of signal strength up there, and I can try it on both coax runs.

    Anyway, thanks again for the replies.
  5. JimSpence

    JimSpence Just hangin'

    Sep 19, 2001
    Binghamton, NY


    The power inserter for an antenna mounted amplifier should be on the line above the diplexer. And the diplexers used need to be power passing on the satellite side only. This way the switching signals sent by the receiver to the LNB or multiswitch isn't shorted by the antenna.

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