need help grounding CB antenna on JK

[turnbull]

I recently installed a new CB antenna on my JK, but I am having an issue grounding it. I thought that grounding it to the frame would work, but it didn't.

So for those of you who own a JK and have mounted a CB antenna on it, how did you ground it?

[NJKURPat]

I don't have my antenna grounded, but I have the actual CB grounded. When I wired it to the battery I went behing the glove box and through the firewall, the grounding wire I kept inside the cab. If you look behind the door restraining hook in the foot well there is a green screw with another wire grounded to it (i think), thats where I grounded mine. If you need a picture let me know.

Haven't really worried about grounding the antenna, but it's on the list to do eventually.

[turnbull]

Unfortunately I have to ground the antenna because some of my channels are giving me an SWR above 3, even after tuning. I may ground to those screws you are talking about, but I'd like to avoid that if possible because that would require running a ground wire essentially the length of the vehicle.

I see a lot of tire carrier-mounted antennas, so I figured there should be an easily accessible ground back there, but I can't find out how they ground their antennas.

[turnbull]

Well I ran a ground wire to the screw you were talking about, and it fixed my SWR issues. Thanks for the suggestion.

[TerryD]

I don't know much about JKs but I was wondering where you have the antenna mounted that you don't have a ground?

[turnbull]

It's mounted in the rear license plate.

[TerryD]

Do you have pictures of how it's done?

[turnbull]

Here are 3 good pictures at this link: http://www.cooltechllc.com/wrangler-par ... ystem.html

You can see where the mount is installed in the license plate holder and what it looks like when it's done.

[TerryD]

Interesting. The self tapping screw doesn't go into the body? I would have thought that would help provide a sufficient ground.

[turnbull]

I do not believe the kit comes with a self tapping screw. You are supposed to use the supplied large washer to ground the antenna.

The antenna is grounded through the mount (inside the license plate), and the studs of the mount go through preexisting holes in the body. On the "inside" of the body where the taillight is mounted, you secure these studs with nuts. The instructions say to sand the body down and use the washer on one of the studs to provide a good ground. Not only would that have been a pain because you have limited mobility sticking your hand through the taillight hole, but I also did not feel like risking the body rusting to get a good ground.

Instead I ran a ground wire from the stud to a frame bolt. The frame bolt must have some kind of clear finish because it did not provide a good ground, and I could not get continuity anywhere on the bolt. Good job on Jeep's part in attempt to resist rusting, but I just didn't expect that.

[TerryD]

Well, while the wire will provide some means of ground, it's hard to say how good it is at frequency. You should try to sand that and use the washer like it said. You can go back and hit it with touch-up paint afterward to seal everything and prevent rust. RF needs more than simply a wire to ground properly in this situation. A 1/2" wide or wider ground strap would work much better and create a better ground. I did this on the hatch of my Cherokee rather than depending on the hinges and latch to create a ground. I had a perfect 1:1 on it and managed several contacts over 10 miles even off the weak side. Chances are that your ground between the frame and body is iffy at best in this situation as well. That being said, most offroad CB's don't need to be overly efficient to talk vehicle to vehicle. Anything under a 2:1 should be ok.

[turnbull]

Since the frame bolt didn't work, the ground wire now runs almost all the way up to the pedals. All channels are now below 1.5, and most are closer to 1. That is good enough for me. When I was using a magnetic antenna, my SWR was in the low-mid 2s.