Roamio OTA Reception Problems with large attic antenna

Discussion in 'TiVo Roamio DVRs' started by Davidhmd, Jan 5, 2019.

  1. Davidhmd

    Davidhmd New Member

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    Jan 5, 2019
    When watching and recording TV, I'm getting choppy images and sound on most channels despite signal strengths that I thought would be strong enough. The Problem gets worse on windy days. Because there is so much signal strength fluctuation in all the problem channels, I'm wondering if I'm having multi-path issues?

    I would greatly appreciate any help you can share. Thanks.

    This table link combines the TV Fool signal data with 3 more columns at the end that show the results I'm getting.

    I can't see any pattern that explains why only channels 9 and 12 are consistently good.

    My setup:
    • Someone gave me a large used roof antenna including mast, but it's currently installed inside my attic without the mast.
    • It's aimed at 240 degrees based on Iphone compass, and is around 20' off ground.
    • It has a lot of close wood contact because its surrounded/weaved into my attic trusses.
    • All cables are new quad-shielded RG6 cable.
    • Cables run from antenna to a 2-way splitter. Line 1 goes to TV ROAMIO OTA, then HDMI cable to TV. Antenna Line 2 goes straight into a TV in another room, which gets better reception than the TIVO set up.
    • My antenna in attic - Pic 1
    • My antenna in attic - Pic 2
    • Link to similar antenna
    • TV Fool: Raw Signal Report
    • The back of my house faces a strip of woods with many tall trees at 210 on compass.
    • There is also one large tree beside my house at 110 on compass, and my antenna is now on the opposite side of the house from that tree.
    Which should I try next?
    • Should I try a different compass setting. (If I re-positioned it in the middle between the attic trusses to get it away from the wood, I would have to point it either 102 or 296.)
    • If I should try an attenuator, what db #?
    • If I must mount the antenna on the roof, I could, but I would prefer to avoid it if possible.
    • Are there other options?
    I already had this TA-25 amplifier. I just tried it, and it didn't help at all.
     
    Last edited: Jan 8, 2019
  2. kpeters59

    kpeters59 Well-Known Member

    1,721
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    Jun 19, 2007
    Houston, Texas
    I've had very good results combing 2 cheap 'leaf' type antennas in an attic using just a standard splitter, to cure a similar problem.

    -KP
     
  3. Jim1348

    Jim1348 Active Member

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    67
    Jan 3, 2015
    I also have a Tivo Roamio OTA and use an attic mounted antenna. I am a bit farther from my nearest transmitter at about 20 miles or so.

    First off, I strongly suspect that you are, indeed, suffering from MPDI (multi-path distortion interference). It is pretty much a given, at least in my mind, with an attic mount antenna.

    With that in mind, you simply have to determine how much effort (time) and money you want to put into this. If you decide to mount an antenna outside, what is the furthest channel you want to try and receive? If you just want the cluster at 13 miles, that should be the easiest. An antenna mounted outside, even at a rood level might do it.

    Obviously, if you want to get more channels, further away, then some additional height might be necessary. Have you talked to any of your neighbors who are very close to you? What antennas do they use and what channels do they get?

    Now if you really want to work a bit more on the indoor installation, like I did, you might want to consider a different antenna design. I happened to go with an 8 bay bow tie array. They offer a lot of gain on UHF. Most of your channels are on UHF, BUT a couple are on (real) RF VHF. The good thing about 8 bay bow tie arrays is that they will do okay on the higher VHF frequencies even though they aren't designed for VHF.

    I would also encourage you to do more research on indoor antennas and MPDI. I was able to find a "sweet spot" for mine. There is at least one UHF antenna made that is designed to be pointed in two different directions. I don't have one and have never used one. It might be worth a shot, though.

    It also looks like it is a bit tight in your attic. Maybe a different UHF antenna would fit and work better. I guess one "plan" could be to try and get it to work in the attic and them, if you can't get satisfactory results, mount it outside.

    You should also take a look at the AVS Forum-Local HDTV Info and Reception. There is a LOT of great information there.

    Washington, DC / Baltimore, MD - HDTV - AVS Forum | Home Theater Discussions And Reviews

    Local HDTV Info and Reception - AVS Forum | Home Theater Discussions And Reviews


    UPDATE:

    Another thing you could give some thought to is modifying your existing VHF-UHF antenna. Once you post what the must have channels are for you we can get into that a bit more. For example, if you said that you want 7 and 9 (real), but don't care about 5, you can cut the longer low VHF elements to be resonant on 7 and 9. You probably already know this, but the reason those antennas are so large is because the log periodic design covers a wide swath of spectrum. The lower legacy VHF channels 2-6, required the longest elements. So, if you tell me that WMDE is too far away AND you don't care about its content anyway, please let me know.

    I have an older version of this: CM-4228HD EXTREMEtenna 80 | Channel Master While the model number hasn't changed, the specifications did slightly. Google it if you want to know more about exactly what changed.

    If I were buying today, for my house, would look long and hard at this one: Xtreme Signal 8-Bay Bowtie Outdoor HDTV Antenna 70 Mile VHF/UHF (HDB8X) from Solid Signal It should work well at your location WITHOUT an amplifier, unless you are running to multiple rooms inside the house. The reviews look favorable with regard to MPDI issues.
     
    Last edited: Jan 6, 2019
  4. just4tivo

    just4tivo Active Member

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    Dec 9, 2015
    Do you happen to have a metal roof?
     
  5. Davidhmd

    Davidhmd New Member

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    Jan 5, 2019
    Thank you all.

    I'm only interested in getting strong and very stable signals from the nearby stations on this table. The furthest stations are 24 miles away. Channels include VHF channels 7, 9, 12, & 13 and several UHF Channels from 4 to 50.

    If I could get completely stable versions of ALL the green channels on this table, that would be good enough, but it would be nice to get the additional PBS stations in the yellow range (27 and 32).

    I don't have a metal roof. Standard roof construction (asphalt shingles over OSB sheathing).
     
    Last edited: Jan 8, 2019
  6. kpeters59

    kpeters59 Well-Known Member

    1,721
    316
    Jun 19, 2007
    Houston, Texas
    Did I mention the dual antennas through a splitter and how well that worked? Using inexpensive antennas? Maybe I forgot to mention how it seems to cancel out Multi-Path? Or, maybe I forgot to mention how simple it is to try?

    Hook up one antenna, optimize it for one 'set' of channels and lock it down. Then, disconnect it and hook up the second antenna. Optimize it for the 'other' set of channels and lock it down. Then run them both in to a slitter and the 'out' to the TiVo.

    -KP
     
  7. 19972000muskrat

    19972000muskrat Member

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    Jan 2, 2008

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