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VHF / UHF Mobile Mount Options

Discussion in 'Mobile Radio Systems' started by N9NY, Dec 30, 2019.

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  1. N9NY

    N9NY XML Subscriber QRZ Page

    Hi everyone

    I have given up on through the roof mounted NMO mounts. Got tired of forgetting about the antenna, having it pull the mount off the roof deck on my 2017 Jeep Cherokee. I run a Kenwood TM V71

    I use a Comet dual band antenna which is 36 Inches tall.

    I am exploring optional mounting systems. One, using a luggage rail rack mount or a lip mount. In the reviews for a luggage mount, users say that the SWR is an issue because the antenna is raised of the roof by more than 3 inches.

    Curious if anyone is using the luggage mount and what type of results you have gotten or is it better to use a lip mount?

    Like many HAMS, I overthink things.

    Happy and Healthy 2020

    Gregg N9NY
     
  2. KB0MNM

    KB0MNM Ham Member QRZ Page

    I used the motorized luggage mount ( K5000, I think- the only one that was made by Diamond ) with a combination 2M/70cm antenna element. The SWR was a bit higher, yet my effective range was greater. The only issues were these: 1. If I failed to periodically tighten the knurled surfaces together ( think about gears with low teeth on the sides, not outside edges ) the elevation adjustment would fail. That can break an antenna. 2. The antenna coax lead length for the back of a mini-van was better at 20 ft. or so if the radio was mounted up front. 3. The up/down switch cover ( not the tiny switches inside ) tended to wear out after only 2 years or less. 4. The coaxial cable supplied was smaller than regular RG-8X/RG-58 and used a special connector. The benefit is getting through a smaller hole. The replacement of the connector ( if needed ) is not as easy as a conventional PL-259. If I were to do this again, I might choose a lip-mount and go lower to avoid folding the antenna down. There are plenty of parking garages everywhere, and motorized mounts are a way to get best use from that luggage rack- until the switch is not used and the antenna breaks.
     
  3. N9NY

    N9NY XML Subscriber QRZ Page

    Thanks!
     
  4. M0GVZ

    M0GVZ Ham Member QRZ Page

    Then get a Breedlove Mounts puck mount. You'll not pull that off.
     
    AG6QR likes this.
  5. KX4O

    KX4O Ham Member QRZ Page

    I guess this depends on the type of antenna used on the luggage rack. I've had success with the groundless model from Diamond mounted on my roof rail. Measurements and thoughts on these two pages...
    The mount has an adjustment to tilt the antenna down when going in garages and such. In theory you could leave this just enough tight to hold up to wind, but bend over when hitting an obstruction. Anyway, just an idea to consider. Works very well for my situation. GL.
     
  6. AG6QR

    AG6QR Premium Subscriber QRZ Page

    I've done a few of the above discussed options.

    My first mobile antenna was a 1/4 wave whip on a luggage rack mount, on top of a minivan. It worked for local repeaters, but when I got an analyzer, I realized how bad it was. And when I compared performance to that of my friend's mobile installations, it was confirmed. About 3.5:1 SWR and lousy performance.

    I switched to a "no ground needed" Diamond NR770HB, but since it was longer, I mounted it lower, on the rear hatch of the minivan. The garage clearance of the longer antenna mounted lower was about equal to the quarter wave on the luggage rack, but SWR was near perfect, and performance was very good.

    When I got a small commuter car, I drilled a hole in the middle of the roof, and mounted a sturdy Breedlove NMO puck up there. I have a Comet dual band whip on it, which is approximately 1/4 wave at 2 meters. It has very low SWR and excellent performance. It's extremely sturdy and reasonably compact.

    I wouldn't recommend using a luggage rack mount with an antenna that needs a ground plane. That NR770HB would perform very well on the roof rack, I expect, but the garage clearance was a deal-breaker for me. It works well enough when mounted lower.

    A Breedlove NMO mount will be the strongest part of your antenna system. If something breaks, it will be either the antenna or the roof itself.
     
    KX4O likes this.

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