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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.

Alright CB geniuses, get in here please!

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Old 11-07-2014, 02:41 PM
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Hey there Nickelsville.

If I missed someone else saying it, sorry. Your problem is that you have the insulation (plastic) washer on the wrong side.

The reason is this: You have a core and a sheath on the coax. Your Firestik should have contact with the core only and be isolated from the sheath. The sheath should have contact with your vehicle body but not the Firestik. That's because the Firestik actually makes up half the antenna and your vehicle body serves as the other half... this makes a full dipole. So, your antenna/core needs to be isolated from your mount. That is what the plastic washer is fore. In addition to the Firestik making contact with the body, your coax sheath is making contact with nothing. It NEEDS contact with the body and the plastic washer is preventing it from doing that.

Switch up so the plastic washer is on top between the antenna and the mount.

Edit - I have an antenna analyzer that will be a lot better than your radio SWR mount. Let me know if you need me to check it for you.
Old 11-07-2014, 03:40 PM
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Originally Posted by Sparkplug
Hey there Nickelsville. If I missed someone else saying it, sorry. Your problem is that you have the insulation (plastic) washer on the wrong side. The reason is this: You have a core and a sheath on the coax. Your Firestik should have contact with the core only and be isolated from the sheath. The sheath should have contact with your vehicle body but not the Firestik. That's because the Firestik actually makes up half the antenna and your vehicle body serves as the other half... this makes a full dipole. So, your antenna/core needs to be isolated from your mount. That is what the plastic washer is fore. In addition to the Firestik making contact with the body, your coax sheath is making contact with nothing. It NEEDS contact with the body and the plastic washer is preventing it from doing that. Switch up so the plastic washer is on top between the antenna and the mount. Edit - I have an antenna analyzer that will be a lot better than your radio SWR mount. Let me know if you need me to check it for you.
Okay. I think I've got it now! So if I ground the sheath to the bracket, the bracket is ground to the tail gate. So ground the tail gate to the body and I'm good? I'm going to have to do this in the dark tonight and hopefully it works tomorrow.
Old 11-07-2014, 03:44 PM
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Originally Posted by ShawnInPaso
I'm supposing you already read the manual - https://www.cobra.com/sites/default/...s/29LTDCLA.pdf If you have the switch in the S/RF position and the meter swings all the way to the right AND when the meter is set to the SWR position and it reads less than 3 then you should be good to go. PS> I grounded my tailgate to the body of the Jeep. There is a bolt on the right side of the back that I used for one side of the ground and then I ran the grounding wire near the hinge up thru the tail gate to the antenna mount.
Lol yes I reluctantly read the manual and keep them all (winch, cb, etc) in the glove box. The built in SWR meter reads full, then almost immediately drops with a VERY brief lag around 2-2.25.
Old 11-08-2014, 01:06 AM
  #24  
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Stud mount should look like this....

Old 11-08-2014, 01:22 AM
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Originally Posted by OH9JK
Stud mount should look like this....
Yup, that's how I have it now. I sanded the bottom side of the mounting bracket to ground the outside/sheath of the coax with out touching the core/antenna. Then I ran a grounding wire from the tailgate to the tub. Still does the same thing as before. I guess we'll see if it works today on the trails.
Old 11-08-2014, 04:29 AM
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Originally Posted by JK505
Okay. I think I've got it now! So if I ground the sheath to the bracket, the bracket is ground to the tail gate. So ground the tail gate to the body and I'm good? I'm going to have to do this in the dark tonight and hopefully it works tomorrow.
Yes, but I didn't make you think you need to run some sort of a wire from the coax sheath to the bracket. That isn't necessary. The connector is designed so that the sheath contacts the outer part of the connector and the core contacts the middle of the connector. You can see what I am talking about if you look closely at the connector. That's just the way you do it when you put a connector on the coax.

All you need is for the outer ring of the connector to contact the bracket and not the core. You need the core to contact the antenna and not the bracket. PM me if you want to stop by somewhere and I will look at it with my analyzer. I'm right on the state line.
Old 11-08-2014, 10:12 PM
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Originally Posted by Sparkplug
Yes, but I didn't make you think you need to run some sort of a wire from the coax sheath to the bracket. That isn't necessary. The connector is designed so that the sheath contacts the outer part of the connector and the core contacts the middle of the connector. You can see what I am talking about if you look closely at the connector. That's just the way you do it when you put a connector on the coax.

All you need is for the outer ring of the connector to contact the bracket and not the core. You need the core to contact the antenna and not the bracket. PM me if you want to stop by somewhere and I will look at it with my analyzer. I'm right on the state line.

So I have no idea what I did.

BUT! I did what made sense in my mind and the CB worked today. I get an antenna warning on channels 1-7 but the rest work great. Thanks for all the help everybody. Had a great day of wheeling and no CB issues.
Old 11-09-2014, 09:22 AM
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Originally Posted by JK505
So I have no idea what I did.

BUT! I did what made sense in my mind and the CB worked today. I get an antenna warning on channels 1-7 but the rest work great. Thanks for all the help everybody. Had a great day of wheeling and no CB issues.
Higher SWR on the lower frequencies but ok on higher frequencies means your antenna is too short. Higher SWR on higher frequencies but ok on lower frequencies means your antenna is too long.
Old 11-09-2014, 10:00 AM
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Originally Posted by Sparkplug
Higher SWR on the lower frequencies but ok on higher frequencies means your antenna is too short. Higher SWR on higher frequencies but ok on lower frequencies means your antenna is too long.
Alright well I'll adjust the antenna up today and see what happens. I also was told there's s cb shop nearby that'll take s look and tune it for free.
Old 11-09-2014, 10:09 AM
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Originally Posted by JK505
Alright well I'll adjust the antenna up today and see what happens. I also was told there's s cb shop nearby that'll take s look and tune it for free.
The only one I know of is kind of on the north end of Johnson City, toward Boone's Creek. I was in there two weeks ago and he had moved out almost everything. He said he was retiring. But... I would be happy to tune it for you. Just let me know.


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