Cobra 29 LX Antennae issues

TANK

TANK

New member
Ok, so last week I went ahead and picked up a Cobra 29 LX, Tuffy Overhead console, Firestik II, and Firestik 18' antennae coax. I went ahead and installed everything this past weekend taking my time to do things the right way.

I installed the bracket for the antennae onto my Expedition One Tire carrier and made sure to grind off the powdercoat on the carrier where the bracket mounts up as well as install a 10 gauge wire from the bracket to the tub for a ground. I've double and even triple-checked my work and found no errors.

Upon trying to tune my cb and transmit to set the SWR I instantly get a antennae warning. I've searched and read up on here and pulled out my multi-meter to check continuity and sure enough I'm getting a beep checking the spring on the antennae to the mounting bracket. I pulled the antennae mount apart to make sure the nylon washer was installed correct and no threads were touching. I have made sure that the antennae is isolated from the bracket 100% yet I am still getting continuity no matter what I do. I even checked the coax running through the rear to make sure there are no cuts or nicks.

I am at a loss as to what it could be or what I'm missing.
 
CZEBJKU

CZEBJKU

New member
Have you tried eliminating the spring and mounting the antenna directly to the mount?

Sent from my SM-N900V using WAYALIFE mobile app
 
TANK

TANK

New member
Though I didn't see it changing anything, I did remove the spring and I'm still getting the same results.
 
cozdude

cozdude

Guy with a Red 2-Door
When i had this issue i all needed to do was grind the powder coat off of my or-fab carrier on the top, bottom, and inside the hole for the antenna. i would double check to make sure you grinded enough off. other than that i cant help, sorry

edit- i see you grinded off the coat where the mount meets the carrier but didnt mention if you grinded off the powder where the antenna mounts to the mount. did you grind that off as well?
 
Jackal01

Jackal01

New member
If I understand your issue correctly...My understanding of the FS 2 antenna is that it does not require the ground wire if the antenna and mount are attached to bare metal. Did you make sure to grind off the metal everywhere that the antenna touches the bumper? The ground wire should not be required if the antenna is mounted to metal (with a good, solid mount). I use the same antenna and I had to grind more paint off and DC the ground wire before my SWR meter was reading correctly after proper tuning. Anything that the mount or antenna mounts to needs to be bare steel/metal. That is at least how I went about getting my antenna tuned. I am sure more CB savvy people will come along.
 
CZEBJKU

CZEBJKU

New member
TANK said:
Though I didn't see it changing anything, I did remove the spring and I'm still getting the same results.
Click to expand...

Did you install the fitting on the end of the 18' coax that connects to the back of your radio? The reason I ask is, that is typically where a short can appear which could cause the antenna warning .Double check the connection with your multi meter and also do an end to end check of the coax.

Sent from my SM-N900V using WAYALIFE mobile app
 
TANK

TANK

New member
Ok, so here's where I'm at: The expedition one mount for the antennae actually comes with just a cadmium finish, so there was no need to grind off the finish. Also, after pulling apart the overhead console I realized that somehow between the lack of space in the back of the tuffy and tightening down the connector onto the back of the cb that the back of the connector actually separated itself. So I'm now waiting on a new connector and a 90° adaptor to be delivered so I can give it another go. I'll let you guys know how it turns out. I appreciate all the help.
 
CZEBJKU

CZEBJKU

New member
TANK said:
Ok, so here's where I'm at: The expedition one mount for the antennae actually comes with just a cadmium finish, so there was no need to grind off the finish. Also, after pulling apart the overhead console I realized that somehow between the lack of space in the back of the tuffy and tightening down the connector onto the back of the cb that the back of the connector actually separated itself. So I'm now waiting on a new connector and a 90° adaptor to be delivered so I can give it another go. I'll let you guys know how it turns out. I appreciate all the help.
Click to expand...

Glad you found the problem. :thumbup:

Sent from my SM-N900V using WAYALIFE mobile app
 
TANK

TANK

New member
So parts showed up late Saturday afternoon, and due to weekend plans I wasn't able to get to it until after work today. I'm happy to report that my issue is solved. What I learned is not to over crank the connector for the antennae and then shove into less than ideal space without a 90° adaptor. The backing on the screw on part of the connector literally gave out causing the bad connection and antennae warning. Everything is back together, tuned, and ready to go.
 
TANK

TANK

New member
Me too! I was about ready to check the antennae wire all the way from the tire carrier through the rear and all the way up the sport bar.
 
H8ROADS

H8ROADS

Caught the Bug
TANK said:
Me too! I was about ready to check the antennae wire all the way from the tire carrier through the rear and all the way up the sport bar.
Click to expand...

I'm about to tackle this over the week as well, just started yesterday with my ant mount. I hope i don't run into this, but I've seen it before. I had to add a rather large grounding strap to my last setup in order to get things to ground right.
 
TANK

TANK

New member
Just make sure your connections and grounds are good and you should be set. I just made sure that I ground down the powdercoat where the bracket attaches to the tire carrier and ran a ground from that to the tub as well. I also had to attach a grounding strap from the cb to the tuffy overhead console per the instructions. All was good though after I replaced the connector to the back of the cb as I'm getting a SWR of 1.2 across the channels. I just want to take some silicone to the edges of the bracket so that I prevent any rust from occurring where I ground off the powdercoat.
 
MedixJK

MedixJK

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Ok little bump on this. Ive got a cobra 29lx. Swr is below 1 on all channels and reception seems pretty good. Still getting antenna warning when i key up. Ive ground off all powdercoat on the mount that would prevent grounding. Everything seems to check fine except for this warning. Any ideas?
 
branman

branman

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MedixJK said:
Ok little bump on this. Ive got a cobra 29lx. Swr is below 1 on all channels and reception seems pretty good. Still getting antenna warning when i key up. Ive ground off all powdercoat on the mount that would prevent grounding. Everything seems to check fine except for this warning. Any ideas?
Click to expand...

Bad Grounds are 99% responsible for this issue - The only way to really know is to check ground with a meter. There are plenty of videos on how to do this. I run a wire from the negative terminal then check all you grounding locations to make sure you have a clean path to ground. I would also check the ground on the radio end. You can also check you coax connections - If you have another cable I would run it out side the jeep to the antenna just to be sure your coax/connectors are not damaged. Good Luck

oh yea - this is going to sound silly but make sure you coax plug on the radio side is truly plugged in all the way.
 
MedixJK

MedixJK

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branman said:
Bad Grounds are 99% responsible for this issue - The only way to really know is to check ground with a meter. There are plenty of videos on how to do this. I run a wire from the negative terminal then check all you grounding locations to make sure you have a clean path to ground. I would also check the ground on the radio end. You can also check you coax connections - If you have another cable I would run it out side the jeep to the antenna just to be sure your coax/connectors are not damaged. Good Luck

oh yea - this is going to sound silly but make sure you coax plug on the radio side is truly plugged in all the way.
Click to expand...

Im hoping thats all it is. Gonna run a coax like you said just to rule that out. Whats the best way to ground one mounted like this? If ground is the issue, grinding powder coat off didnt help.
 

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branman

branman

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MedixJK said:
Whats the best way to ground one mounted like this? If ground is the issue, grinding powder coat off didnt help.
Click to expand...

First I would remove the spring until you get it solved as the spring makes your antenna longer (in the swr world) and it could be broken inside.

Did you grind the powder coat off here? (see pic) This is where the antenna gets to ground - also are the 2 bolts/washers making contact with metal or powder coat? because the bracket is isolated from the tail gate.

Look at it this way - path to ground - bottom of the antenna stud travels thru the bracket under the powder coat to the mounting bolts thru the tail gate to ground. so if any of the bold items are block from another you have a bad path to ground.

a1.jpg
 
MedixJK

MedixJK

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branman said:
First I would remove the spring until you get it solved as the spring makes your antenna longer (in the swr world) and it could be broken inside.

Did you grind the powder coat off here? (see pic) This is where the antenna gets to ground - also are the 2 bolts/washers making contact with metal or powder coat? because the bracket is isolated from the tail gate.

Look at it this way - path to ground - bottom of the antenna stud travels thru the bracket under the powder coat to the mounting bolts thru the tail gate to ground. so if any of the bold items are block from another you have a bad path to ground.

View attachment 140485
Click to expand...

I ground the bottom side of stud hole and around each of the two bracket mounting bolts, all to bare metal. I was thinking along the same ground path as you mentioned.
 
JayKay

JayKay

Caught the Bug
I'm gonna dig up this older thread for a minute...I have a 29LX, 18' unknown brand Coax, and a 4' Firestik antenna. I've had this setup installed for close to a year with no issues. Well after a recent wheeling trip back in September, I started getting the "CB antenna warning" on all channels when keying the mic. It worked fine the whole trip. Turned it on while on the freeway a couple weeks ago and that's when I noticed the issue. I noticed I get good receiving signal but can't broadcast out without the warning. I did grind the paint off the mounting surface and cleaned up the mounting surface of the bracket to no avail. I have a feeling the coax is bad, but I would think I wouldn't have signal at all. I checked SWR with my external meter and it pegs the needle high anytime the mic is keyed. Can someone give me some input before I replace the coax on a hunch?
 
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