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What I did for our JK CB System

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  • What I did for our JK CB System

    There have been a few discussions on CB's here lately so I thought I would type this up to share. There's some really good info provided in the thread CB How to / Setup / Question and answer thread but I'm going to tell you what I did and skip most of the technical stuff.

    The absolute most important aspect of a CB system is the antenna setup. The most important part of the antenna setup is proper grounding. The second most important part of the antenna setup is placement.

    So to get started here are the "antenna" parts that I ordered.
    DISCLAIMER: The manufacturer's website leaves a lot to be desired but can be found at http://www.firestik.com/index.htm. Therefore some of the following links are to a NON-SUPPORTING VENDOR (FTL Distributing - http://www.ftldist.com/) that I AM NOT AFFILIATED WITH. I do attest to the fact that this is the vendor from which I purchased these items (2013-Sept). That said, for those of you who live in the KC Metro area, you may be able to find these items locally and potentially at better prices than those offered by the company that I linked to.

    3' Firestik Firefly Antenna - The Firefly antenna is tune-able without cutting. It uses a set screw on top to shorten or lengthen the antenna.
    Firestik SS3H CB Antenna Spring Heavy Duty - The spring is completely optional but given that a lot of the wheeling in this area is in wooded environments, a spring might help prevent breaking an antenna.
    Firestik K48R18 18' FireRing Coaxial Cable with K4R Stud - The FireRing cable is setup to make the proper connections by simply bolting it to the mount and antenna so all we have to worry about is the grounding.
    NOTE: The K48R18 cable assembly does require soldering to complete. The end that attaches to the CB must be installed on the cable. The fact that the end isn't installed makes running the cable a thousand times easier however.

    Depending on the placement of the mount you choose, you may need some extra items.
    • A couple of eye terminals, i.e. those little round wire connectors
    • some stranded wire
    • some shrink tube
    • one (maybe two) stainless self tapping screws
    • a wire cutter/crimper
    • a drill
    • a properly sized drill bit to match your self tapping screws


    Speaking of placement...

    In many cases Jeep JK owners choose to place the antenna on the tailgate. This is great for getting the antenna out of the way, it looks cool, and there's several "holes" already there to run an antenna cable into the interior without drilling. There's also a large selection of antenna mounts on the market that use existing mounting points on the tailgate as well. There are a couple of issues that the tailgate introduces however.

    The tailgate is absolutely one of the, if not the worst places for proper grounding. This issue is easily solved with the previously mentioned wire and eye terminals. The next issue is that the mounting locations (a.k.a. bolt holes) are below the top edge of the metal tailgate or worse yet, sandwiched between the metal tailgate and the spare tire (which also contains metal). All that extra metal blocks and reflects the signal and can cause interference. Bascially, your radio sees that feedback like we hear feedback from a microphone/speaker audio loop. OUCH!

    For that reason I bought an Arizona Rocky Road mount. If you know how to weld and have metal stock available, you can make one of these yourself (or if you have a buddy that works stupid cheap) but for $30 I'm not going to complain (plus I can't weld.) The guy makes them for JKs, TJs, and the Jeep Liberty. The beauty of these is in the design. These mounts use existing mount points, they raise the base of the antenna ABOVE the tub as well as the stock spare tire on the JK/TJ, and they have lots of metal to work with to add a ground screw and ground wire.

    Oh yea...grounding...

    To properly ground the antenna with the FireRing cable we have to do two things. First we have to make sure the FireRing cable touches bare metal on our mount and second we have to make sure our mount has a good ground. The FireRing instructions deal with how to attach the FireRing and antenna so I won't duplicate that here. We still need to ground our mount though.

    Using the tools and materials listed above, I drilled a small hole in the base of the mount on the back side. I drilled through the mount plate and into the square tube on the Arizona Rocky Road mount. This leaves the sharp tip of the screw inside the mount so the tip doesn't damage anything. I then attached my ground wire to the mount using a self tapping stainless screw. At that point I ran the wire into the interior. I attached the ground wire with an existing stud/bolt that is under the sub-woofer enclosure on top next to were the roll cage meets the tub. The worst part was running the wires.

    I guess I should at least mention the radio...

    As long as you stick with a name brand radio, e.g. Cobra, Uniden, or similar, your selection really boils down to features (a.k.a bells and whistles) and maybe in some cases size. Size can be particularly important if you opt to mount the radio somewhere "out of the way" such as on the driver/passenger side of the console. I opted for the Cobra 29LX because it happens to have weather radio capabilities, but that's just me. I also built a custom mount for the dash so the size wasn't too much of an issue.

    So there you have it...

    Now you know what I picked, why I picked it, and way more info than you really wanted. :lol:
    Heath
    2016 JKU Rubicon Hard Rock
    2014 JKU Rubicon X Package - Deceased - Thank you for your sacrifice in protecting my family.

  • #2
    Thanks for all of that really good information.

    Just for people who aren't reading carefully, remember that you are grounding your antenna mount and not the actual antenna. If you look at the diagram, or a properly assembled mount, you will see that you are actually grounding the cable's shielding and not the internal connector.

    You also want to make sure you tune your antenna. Find someone with an SWR meter and tune it to less than 2:1. Remember, you've only got 4 watts. If you're reflecting most of it back to the transceiver because of a poor SWR, you're not getting all of that RF out of the antenna and into the air so your communications are going to suck.

    An electrical ground is not the same thing as a ground plane. Even when your mount is grounded, it really isn't contributing as a ground plane. This is why you need to make sure that your antenna is above and away from vertical metal surfaces. Let's face it, our Jeeps suck for this. The best place to mount any antenna on a Jeep is smack in the middle of the hood. You'll get the best ground plane that way, but you're gonna look funny. I don't know about anyone else, but I don't need any help in that area :)
    "People who want to share their religious views with you almost never want you to share yours with them." -Dave Barry

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    • #3
      Originally posted by tfiedler View Post
      ...but you're gonna look funny. I don't know about anyone else, but I don't need any help in that area :)
      Yep...I don't need any help in that area! :)

      Just for reference, if anyone decides to buy a meter, I highly recommend this SWR Meter from Radio Shack. I have a buddy (HAM radio guy) who had several meters and the Radio Shack unit worked and the others didn't. I then stopped at the truck stop in Kearny (on my way to a Jeep Jam in AR) and got one of those $10 jobs. It didn't work either (glad I brought his along just in case.) Also, if you buy a meter, don't forget to pick up a short 3' pre-built CB cable to hook the meter up. CB -> Meter ->Antenna (each arrow represents a cable)

      Lastly...I typically have my meter in my "Jeep box" so if you want some help tuning a radio while were at an event, please don't hesitate to let me know. :thumright:
      Heath
      2016 JKU Rubicon Hard Rock
      2014 JKU Rubicon X Package - Deceased - Thank you for your sacrifice in protecting my family.

      Comment


      • #4
        I drove over the road for years.... before cell phones ! ... all we had was CBs ! .... You can mount to tailgate, if you run a ground wire from gate to body ! ;) Hinges are lousy grounds ! :) set your swr and be happy , I can set mine with radio as it has a built in swr meter ! :) ... course , I run a Cobra 29 ;)
        I may be Rad and I may be Bad :pbj: but I am never SAD ! :kilt:
        Yea I'm *Q*C* and ?
        it is a great feeling to have served your country and walk PROUD
        Yes veterans stand tall and their shadow protects all !

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