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Discussion Starter #1
Installing a 4ft Firestick on an aluminum rear bumper, drivers side. Which is a better position and why; full left behind the rear flare center line or behind the tail light protected from trail hazards?
Mounted to the aluminum, will I need to ground the antenna mount?
Thanks,
Wooly


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You won't need to worry about grounding.

Since it is only 4' tall, putting it outside the edge of the side of the Jeep might make a bit of difference in how well it works in certain conditions. But not really enough to make up for it getting hit by brush. Make sure it is outside the window when open, and does not interfere with the door opening. No real advantage being on the left or right in this case. I run a 102" and you want to run those on the right side. That way they clear the drive thru's at fast food and at ATM's better.
 

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Bumper mounted antennas never work as well as one whose mount is up higher like at taillight level. Bumper mounted antennas have too high of a percentage of their length next to the steel tub which degrades the antenna's performance and also makes it harder to tune to a good low SWR. Install a mount higher up, like at tail light level, and go with a shorter antenna which will simply work better.

This is the most popular general height for CB and ham antenna mounts for Wranglers since it elevates the antenna up above the steel tub.
 

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If the bracket has paint on it where the bolt goes into the bracket, you must grind the bracket so the bracket and bolt can make a ground to the tailgate, (paint it after install with a small brush). Also grind the bottom side of the antenna mount where the antenna hole is. If you don't have a ground, SWR will be way too high and you could blow up the radio if you transmit on it. Good luck!
 

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If the bracket has paint on it where the bolt goes into the bracket, you must grind the bracket so the bracket and bolt can make a ground to the tailgate, (paint it after install with a small brush). Also grind the bottom side of the antenna mount where the antenna hole is. If you don't have a ground, SWR will be way too high and you could blow up the radio if you transmit on it. Good luck!
Good suggestions though modern CBs have had automatic protection circuits built in for many years to protect against high SWR levels. They had too many warranty claims during the CB craze of the 70's and 80's from too many people not knowing how to install an antenna.

To add a little more info on where to grind the paint/powder coating off the bottom of the mounting bracket, here's a quick diagram. The top of the SO-239 Coax Connector, see below, needs to be touching bare metal so grind a ring around the bottom of the hole opening from here. Don't grind the paint/powder coating out from actually inside the hole itself.
 

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Bumper mounted antennas never work as well as one whose mount is up higher like at taillight level. Bumper mounted antennas have too high of a percentage of their length next to the steel tub which degrades the antenna's performance and also makes it harder to tune to a good low SWR. Install a mount higher up, like at tail light level, and go with a shorter antenna which will simply work better.

This is the most popular general height for CB and ham antenna mounts for Wranglers since it elevates the antenna up above the steel tub.
I beg to differ with your statement that bumper mounted antennas are never more efficient than those mounted higher up. I have a 102" whip antenna bumper mounted. Very little of it is near the steel body. As long as your SWR is below 2, there is little to be gained as far as performance, but I have never had one of these that would not tune below 1.5 SWR. This one is under that. Shorter antennas are always a compromise. No matter where mounted. Mounting higher up is good, but a 102" is already rather high for daily use. Even if I mounted a shorter antenna, I would still be quite apt to use the bumper mount similar to what I have, but go with a 4' or 6' tall unit.

If you mount at the top of the steel body/tailgate area and from the tire carrier area on a hardtop Jeep, you have the rear defroster wiring to deal with. That will have a bigger effect on signal than what the body gives you!

 

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I beg to differ with your statement that bumper mounted antennas are never more efficient than those mounted higher up. I have a 102" whip antenna bumper mounted.
I agree with you on a 102" whip but those are the exception now. They're rare and getting rarer, not many people run them any more though I did 50 years ago. Especially so that many clubs and organized events started banning antennas longer than about 50" due to 102" whip antennas having caused injuries over the years. Even when they're tied down at the tip since those tip tie downs can give which can cause it to whip backwards viciously.

With the vast majority of CB antennas being 2' to 4' tall, and I can't even remember the last 102" whip I saw on an offroad Jeep, I stand by what I said. :)
 

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Bumper mounted antennas never work as well as one whose mount is up higher like at taillight level. Bumper mounted antennas have too high of a percentage of their length next to the steel tub which degrades the antenna's performance and also makes it harder to tune to a good low SWR. Install a mount higher up, like at tail light level, and go with a shorter antenna which will simply work better.

This is the most popular general height for CB and ham antenna mounts for Wranglers since it elevates the antenna up above the steel tub.

I agree 100%! My antenna is mounted on my rear bumper right now, and the range and signal are horrible. When I was still trucking over the road, that same radio and antenna (Mounted on the mirror of an 18-wheeler) would get me well over 10 miles easily. On the bumper of my Jeep, I'm lucky if I get one mile. I never intended to keep it there permanently, I just haven't had the disposable funds yet for a roof rack. Once I do, my antenna will get moved up higher.
 

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Discussion Starter #9
As I digest the experiences and advice here I see two options based on the following. Original was the 4ft on the rear bumper using the extra height for better range. I have the teraflex mount with 2 holes one for a whip and the other for a 3ft firestik.
3ft firestick with rear defroster interference or
4ft on bumper with metal tub interference? Hate to drill the bumper and find discover it works very poorly.
Votes...


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I talk almost everyday with my with a 3' firestik antenna and the Teraflex mount on the spare tire. SWR is 1.1:1 Also I like the fact it is only about 7' 1/2'' high. Works great. I have had about every good mobile antenna made and the firestik or the firefly 3' or 4' is my favorite, for the Wrangler. Main thing it does not hit when I pull into burger king every day for a whopper!
 

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As I digest the experiences and advice here I see two options based on the following. Original was the 4ft on the rear bumper using the extra height for better range. I have the teraflex mount with 2 holes one for a whip and the other for a 3ft firestik.
3ft firestick with rear defroster interference or
4ft on bumper with metal tub interference? Hate to drill the bumper and find discover it works very poorly.
Votes...
A 4' antenna mounted on the bumper will, again, work poorly.
 
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