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JK CB & HAM Radios Bulletin board forum regarding all topics concerning CB and HAM radios, the installation of them in your Jeep JK Wrangler. This would include antenna mounts, wiring, tuning and usage.

Antenna ground help/advice needed

Old Jan 28, 2012 | 04:31 PM
  #1  
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Default Antenna ground help/advice needed

I am new to CB's, or at least the installation of them. I need advice on how to resolve this problem. Believe it or not, here in San Jose, there are not any CB installation specialists. I have spoken to several auto electric installers, but have had no success.

Here is what I have:
2009 Unlimited. Cobra 75X installed basically where most others have them installed. Control unit under glove box with jack mounted into dash to left of glove box door. I used an 18 foot Firestik coax cable installed under the door stripping, the carpet, and under the subwoofer. It travels through the swing gate's rubber grommet and attaches to a Teraflex swing gate mount. The antenna is a 36 inch Firestik with tunable tip.

Here is my problem:
My SWR is hovering around 3.5 or higher and no tuning is getting it any lower.

My troubleshooting so far:
I have check continuity and lack thereof in all the right places and it is functioning properly. I had one auto electrical guy try grounding the antenna with a wire while I pressed the transmit button, but no success.

What I have not done is made any serious attempt to ground the antenna. There was no mention in all the install instructions that it needed to be grounded. So, in my ignorance, I assumed it was grounded via something in the antenna itself. Obviously, this was a wrong assumption.

My questions:

Has anyone grounded this type of antenna in this type of installation? If so, how?
Do I attach a ground wire somewhere on the antenna and then to bare metal on the swing gate?

Note: I know not to use the CB until this issue is resolved, lest I burn out the unit.

Thanks for any help provided!
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Old Jan 28, 2012 | 04:59 PM
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Do not ground the antenna! The mount that your antenna is attached to is what needs to be grounded. The antenna should have come with a plastic washer, which is on the top side of the mount, between the mount and the antenna. And when you are setting vswr make sure your not around any buildings, and your inside with the doors shut.
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Old Jan 28, 2012 | 05:03 PM
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Here is a picture of the plastic washer.

Click image for larger version

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Old Jan 28, 2012 | 05:05 PM
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Do a search on Interference, HF RFI, grounding... etc.
you basically need to start grounding the Jeep to the frame..

first make sure what minime said isn't part of your problem.

there is some good stuff in some of these posts.

also post pics if possible. that may help if nothing you read does.

Last edited by JK-jeepit; Jan 28, 2012 at 05:39 PM.
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Old Jan 28, 2012 | 05:09 PM
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Are you saying that I'm the problem?
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Old Jan 28, 2012 | 05:27 PM
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Originally Posted by minime
Here is a picture of the plastic washer.

Attachment 271427
Yep, the plastic washer is in place.
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Old Jan 28, 2012 | 05:28 PM
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Originally Posted by JK-jeepit
Do a search on Interference, HF RFI, grounding... etc.
you basically need to start grounding the Jeep to the frame..

first make sure what minime isn't part of your problem.

there is some good stuff in some of these posts.

also post pics if possible. that may help if nothing you read does.
Should I remove the mount and scrape paint from it and the tailgate to ensure the mount is grounded?

Following this, I then need to ground the gate to the frame?

Thanks!
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Old Jan 28, 2012 | 05:30 PM
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Originally Posted by minime
And when you are setting vswr make sure your not around any buildings, and your inside with the doors shut.
I did follow the above testing instructions. I am using the Radio Shack SWR meter. Although not top of the line, I assume it should do the job for which it was designed.
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Old Jan 28, 2012 | 05:33 PM
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Yeah the ground on the mount is very important. Maybe try to put a ground strap to the tailgate from the frame.
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Old Jan 28, 2012 | 05:34 PM
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Does your swr change as you go through the channels?
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