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Has anyone thought of or tried using two/three shark-fin antenna(s) to improve Sirius/xm reception?

Discussion in 'Gen 3 Prius Accessories and Modifications' started by striker308, Nov 8, 2013.

  1. striker308

    striker308 Three time Prius owner

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    I started a new job a few months ago that has me traveling the mountains of central PA and I lose signal a lot while driving.
    I am toying with the idea of installing two more antennas for a total of three across the back all lined up and evenly spaced. Power wouldn’t be the issue as much as connecting all three together, and that raises the question (is this too much gain for the receiver since all three would be amplified?)
     
    #1 striker308, Nov 8, 2013
  2. 32kcolors

    32kcolors Senior Member

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    Other than looking silly, it doesn't make much sense because the Sirius/XM antenna is in the base, not the stubby/whip antenna for radio. A sharkfin serves to connect to the stubby/whip part and merely sits over the existing Sirius/XM antenna base.
     
    #2 32kcolors, Nov 8, 2013
  3. striker308

    striker308 Three time Prius owner

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    Thanks, I forgot about that.

    So that changes thinsg to to include two more bases under the sharkfins.
     
    #3 striker308, Nov 8, 2013
  4. ataylor2

    ataylor2 Member

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    I am planning to just swap it to a standard XM antenna as that has reported to have good results. The way it works now is just kinda embarrassing
     
    #4 ataylor2, Nov 8, 2013
  5. performancenut

    performancenut Junior Member

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    First thought when reading this is that it would look like a French tickler (with several shark fins)...........
     
    #5 performancenut, Nov 8, 2013
    striker308 likes this.
  6. KK6PD

    KK6PD _ . _ . / _ _ . _

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    Duh???.... NO! It's just don't work that way!
    XM down link frequencies are 2320.0-2332.5 MHz. there is also a terrestrial repeater in around the 70 most major cities that also retransmit on "S" 12.5 MHz Band! What you need is a really good antenna. You are in New York so since the satellites are at 115° WL & 85° WL the states have good coverage, you being more north of the equator will receive slightly less signal than I do living in Los Angeles, a bit further south, but closer to the Clark Belt!
    There are several good aftermarket antennas. I have one from Sony. It's about the size of a small 2" puck with a magnetic bottom. Most XM / Sirius Antennas have built in down converters built in so if the antennas electronics are toast, time for a new antenna. Before you tear the car apart, pop the new antenna on the roof, and just plug it in. See how well it works first, then tear your car apart. you want to mount it externally. If the Toyota factory XM antenna is what you are replacing, you may just need a new OEM antenna. You can put it in yourself, but it is a P.I A.!! I think they located the XM unit in the same place as in the Gen II, under the rear passenger seat! Note that this pod also contains the cars FM antenna as well. Gen II had a separate XM antenna! I think Gen III's are all in one unit!

    Good Luck, let us know what you come up with!
     
    #6 KK6PD, Nov 8, 2013
  7. dbcassidy

    dbcassidy Toyota Hybrid Nation, 8 Million Strong

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    I'll just wait for laser com to come to XM Serius, then i'll upgrade.

    DBCassidy
     
    #7 dbcassidy, Nov 9, 2013
  8. striker308

    striker308 Three time Prius owner

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    Job is in PA not NY, I'm talking about a Gen III nota Gen II but thanks for the frquencies leason.
     
    #8 striker308, Nov 11, 2013
  9. striker308

    striker308 Three time Prius owner

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    Barrowed my wifes xm unit with antenna and left the factor unit turned off this trip.

    Same dead spots, since I can't move the mountains I guess this is a non starter.

    Even the cell amp is having a hard time keeping a signal and I boosted the gain on that from 5W to 8W.

    Just a bad area for signal.
     
    #9 striker308, Nov 11, 2013
  10. KK6PD

    KK6PD _ . _ . / _ _ . _

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    XM is same unit in both Gens! Theory of operation is the same for both Gens. You have an antenna / down converter issue. It adds up to it's gonna cost you.

    Wait a minute, you run a Cellphone booster system in your car?
    Try turning it off and see what effect it has on XM.That could overload the front end of the XM receiver! That could be part of the problem!
    If you out in the hills of PA, you should have a good view of the eastern satellite! It sounds like you are only receiving the terrestrial link, and at the frequencies they run, they are not meant to cover all the countryside, just the cities that need it.
    You got a friend with a Prius and XM that wants to make a road trip, see how his car reacts, if it works fine, you need to spend some money!

    ​
     
    #10 KK6PD, Nov 11, 2013
  11. striker308

    striker308 Three time Prius owner

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    I switched off the cell booster today to try it, the booster only boost signals in the 800-900Mhz range but Ive seen stranger signal interuptions with some of the medical equipment.

    No change in signal, strangly enough I drop signal when the western sky is blocked. That has me stumped! I looked up the position of XM satilite in relation to where I'm at and that shouldn't be causing the drop out.

    It did the same thing with my wifes unit, The only thing I can figure now is that I'm "too close" to the side of the cliff in these spots.

    Not much for a work around but I just drive faster in these areas to get out of the dead spot.
     
    #11 striker308, Nov 13, 2013
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