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AgentJeffy
06-05-2019, 09:12 PM
Please. Anyone I don't know what else to do anymore.

I have a Cobra 29 LTD Classic, 18' Firering coax, a 4' Firefly. The Firefly is mounted on the roof of my SUV with the tuning screw removed and the mount attached to my roof racks horizontal bar and is grounded by a wire to the body of the truck. But I can NOT for the life of me get my SWR below 3 on 1 and 40.


Channel 40 is higher than 1 but not by much at all, they're pretty much even. If I put the tuning screw in at all the SWR goes up on both channels. Is it that the antenna is too long because it's on my roof? Or too short? Should I get a regular Firestik? I just replaced the coax and the mount because I assumed it was the problem but it obviously wasn't. I

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mjd420nova
06-05-2019, 11:06 PM
If it was me, I'd go with a top loaded firestick, get as much of the radiating element as far above the base. A double check of the coax and its connections, no crimps, solder the connector and the ground lugs. Besure to clean any paint or rust of the ground connection surface.

AgentJeffy
06-05-2019, 11:46 PM
If it was me, I'd go with a top loaded firestick, get as much of the radiating element as far above the base. A double check of the coax and its connections, no crimps, solder the connector and the ground lugs. Besure to clean any paint or rust of the ground connection surface.
Thanks for the reply.

So something like a KW series?

The coax is good, I'm sure of it. Soldered the connector end of the coax on the Firering cable today. I can go back with a wire wheel and revisit the grounding location. I think it's good but doesn't hurt at all to check it again.

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AgentJeffy
06-06-2019, 11:38 AM
Would it even be worth me trying to trim off some of the tip of this tunable antenna? Or does that not work with these models?

Saw a YouTube video of someone doing that and they swore it fixed up their SWR. Didn't think you could trim these tips though...

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JesseJamesDallas
06-06-2019, 04:49 PM
You might want to give up on the idea of mounting the antenna to the luggage rack...Those things are not grounded, and running a wire may-not be enough to get a decent ground... tried doing that on my old Suburban once, and never could get a decent ground...Best-bet would be either a magnet mounted antenna, or drill a hole and do a permanent mount.

AgentJeffy
06-06-2019, 05:06 PM
You might want to give up on the idea of mounting the antenna to the luggage rack...Those things are not grounded, and running a wire may-not be enough to get a decent ground... tried doing that on my old Suburban once, and never could get a decent ground...Best-bet would be either a magnet mounted antenna, or drill a hole and do a permanent mount.
Ugh, I was hoping that wouldn't really be the case... Everyone swears that the roof it the best place to mount the antenna bar none. I figured running a beefy 10GA wire for the ground would have been enough but maybe it's too long of a run or something?

I was really hoping to be able to get away with it up as high as possible to clear trees as best as I could. Short of changing the antenna to a top load (like a KW series) I've pretty much exhausted all my other options at this point.

JesseJamesDallas
06-06-2019, 09:07 PM
Ugh, I was hoping that wouldn't really be the case... Everyone swears that the roof it the best place to mount the antenna bar none. I figured running a beefy 10GA wire for the ground would have been enough but maybe it's too long of a run or something?

I was really hoping to be able to get away with it up as high as possible to clear trees as best as I could. Short of changing the antenna to a top load (like a KW series) I've pretty much exhausted all my other options at this point.
roof "IS" the best place for the antenna....just not on the luggage racks!

AgentJeffy
06-06-2019, 09:39 PM
Any suggestions you got for me to maybe salvage the spot? Can you really clip the end of the tunable tip antennas without ruining it?

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JesseJamesDallas
06-07-2019, 04:47 AM
Like I said earlier, either use a magnet mount, or drill a hole and install a permanent hockey-puck or ball mount...As for tuning the antenna, you can clip the wire off on those fiberglass type antennas, BUT BEFORE YOU DO THAT>>>Get the antenna mount problem fixed first, or you will just end up ruining a good antenna.

AgentJeffy
06-07-2019, 07:21 PM
Man that's disappointing. I just wanted to get the best circular coverage and overall range out of my CB...

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JesseJamesDallas
06-08-2019, 07:28 AM
Man that's disappointing. I just wanted to get the best circular coverage and overall range out of my CB...

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can you not use a magnet mount? or drill a hole and instal a hockey puck mount?

AgentJeffy
06-08-2019, 11:41 AM
Well I looked into a hockey puck mount but I don't know that they'd hold up well on the highway. The one that uses 3 of the puck magnets looked promising but I have ridges on the roof.

So just so I understand better. Is the problem I'm experiencing because the antenna is roughly 4" ABOVE the magnetic ground?

On top of actually finding a solution (whatever it) I also am interested in learning why this is happening to begin with.

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JesseJamesDallas
06-08-2019, 04:00 PM
Puck mounts will hold any antenna out there...I also know what your dealing with, with the roof ridges, I had that issue with my Suburban, they do make a quad-magnet mount however that has 4 5" magnets which in most cases will let you get around those ridges...plus, ain't no-way a antenna is going to fly off using 4 magnets!

Check out "Breedloves antenna mounts" he has by-far the best antenna mounts money can buy...They cost a little more but they will outlast whatever they are mounted on...I been using his ball mounts for years and never had one fail yet.

https://www.breedlovemounts.com/

AgentJeffy
06-08-2019, 07:52 PM
I just don't know if I have the heart to drill that much into the body to mount the thing...

Too bad there isn't really a good AND durable magnetic mount antenna I could just go to.

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222DBFL
06-12-2019, 12:51 PM
Well as far as magnet mounts go, the best one I have used to date for a single magnet setup is the Sirio PL145. You may need to change the coax out to some better stuff, but the magnet itself is pretty strong for a single magnet setup. Then there are the 3 and 4 magnet setups that are awesome as well. But remember you will have to do some maintenance on any of the to keep them working well. You won’t have this issue with a drill through mount. Just some food for thought.

AgentJeffy
06-14-2019, 05:19 PM
I ended up breaking down and drill mounting the antenna with a Firestik door jamb mount. Put it between my rear trunk hatch and pillar. SWR is a marvelous 1.1 on 1 and 40. Running the Firestik Firering cable and a FSII in 4'. May upgrade to 5'.

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mjd420nova
06-14-2019, 08:29 PM
One alternative would be to mount some grounded elements to the roof rack, like the ground plane on a base antenna. I've seen hubs that mount one fire stick vertical and three at a downward angle to create the ground plane.