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-   -   CB antenna height (http://www.wranglerforum.com/f40/cb-antenna-height-253726.html)

HunterTheBeagle 07-05-2013 03:04 AM

CB antenna height
 
Let me start with saying that I am new to CBs but I am learning and enjoying. My current set up is the cooltech complete kit with the hand held cobra, license plate mount, and 4ft firefly. I have been doing some research on mounting locations for various vehicles and everything I read says to get you antenna as high and centered in the vehicle as possible. My question is how much of a difference would that make with a fiberglass hardtop? My understanding is you want it up high to get as much of the antenna as possible above your roof line. Would I see a difference from switching to a tailgate mount like the teraflex? I'm also switching to a Francis antenna because I can't get my swr down but that's a different story. Thanks in advance for your opinions and advice.

RamP 07-05-2013 04:21 AM

I have a 3' firefly antenna mounted to the tailgate with the Teraflex mount. It extends about 13" above the roofline and I've never had a problem with it on the trail or on the highway to talk to truckers. I've seen guys on the trail have an antenna that barely goes over the roof. On the trail you don't need much range as the guys you will be talking too are usually within your line of sight.
I did have a problem with the coax getting broken from frequently opening and closing the tailgate though. I had followed the exhidting harness from the body to the tailgate and the coax broke from the severe bend. I had to rout it a different way.

HunterTheBeagle 07-05-2013 06:08 AM

Thanks ram that does bring up an interesting point. I am talking about highway range. Once I get my swr problem fixed (crossing my fingers) I should be good for trail purposes. I understand that I will probably never get the range that a steel whip or better antenna will. But I'm just trying to get the Max out of my setup. The reason that I realized I had an swr issue was because I was only receiving and transmitting about a quarter mile or less. That's what got me to thinking about how I can increase my range in general.

HunterTheBeagle 07-05-2013 06:10 AM

About how far would you say your getting out with the three foot firefly?

GoldenSahara00 07-05-2013 06:22 AM

I have a 4 foot firefly on the rear bumper. 8-10 once was above the soft top. Works fine.

BlueRidgeYJ 07-05-2013 07:02 AM

As high as possible on the rear passenger side will give the best forward-range for highway use.

The centering on the vehicle is to allow the metal of the Jeep to act as a groundplane, which essentially bounces the radio signal from the antenna into the atmosphere. Having it centered gives an almost symmetrical broadcast pattern, while offsetting it can provide directional range. In laymans terms, put the flat metal between where you broadcast and where they are, it'll 'bounce' right to em.

Are you certain your mount is connected properly? If the mount is not properly bonded you will have high swr, I would look at that before replacing my antenna.

2', 3', and 4' antennas all work well, mainly depending on how high on the vehicle they are mounted. The higher, the better. For instance, a 4' on the bumper is about as good as a 2' on the tire carrier and a 3' on the taillight. The only thing that will noticably outperform a high-mounted 4' is a 102" SS whip, which can cause damage or serious injury while offroading (which is why we don't use them). Most users wouldn't notice much, if any, difference in a carrier mounted 2, 3, or 4 ft antenna. The main goal is getting it up above any verticle metal paneling, like the tailgate or spare.

Way more to it than that, but I hope this helps. :)

HunterTheBeagle 07-05-2013 08:13 AM

Absolutely! That def helps and makes sense as well. Sounds like for my use it really would not be worth the time to rewire it just move the mount over to the center.

As far as my current mount goes I installed it per instructions then double checked it to make sure it was correct, then also ran an extra ground wire to make sure it was well grounded. After I realized my swr was too high the first thing I did was checked to make sure I was still well grounded... and it seemed to be. I checked the mount and the body with a meter and that seemed fine. So I started to try to tune. I started with the tunable tip and coundent get it to come down at all so I started to cut off the wire a quarter inch at a time. After about 6inch or so it came down a little but not by much. So for 20 bucks I figure I will see if I just have a bad antenna.

I emailed cobra and asked them about the issue and that was their suggestion.

Jerry Bransford 07-05-2013 11:11 AM

A high SWR on the type of antennas we install on our Jeeps, especially when that antenna is a Firestick product, is normally caused by the mount or installation. It usually takes someone with antenna experience to spot the problem causing the high SWR. I've had people come over to my house for help with high SWRs who swore the mount was done properly, only to find a problem somewhere in the mount installation process. Your best bet is to drop by a CB shop & have an experienced tech take a look.

HunterTheBeagle 07-05-2013 04:54 PM

OK thanks everybody, sounds like a trip to the cb shop is in order.

BlueRidgeYJ 07-05-2013 07:38 PM

Quote:

Originally Posted by HunterTheBeagle (Post 3930521)
OK thanks everybody, sounds like a trip to the cb shop is in order.

If ya got one nearby, that's your best bet. Your antenna is likely bonded, or your mount isn't. Just an FYI - If your swr is above 3 across the board, there is (almost) always an install issue.

Jeep4l 07-06-2013 06:41 PM

Also make sure you installed it correctly especially when connecting the antenna to the coax via the mount (For the story, I did it wrong the first time and got a good SWR until I did hit the transmit button)

http://www.stu-offroad.com/cb/ant-mount.jpg

HunterTheBeagle 07-06-2013 09:57 PM

Sweet! Thanks for the graphic :thumb: that helps I won't be able to take a look at it or take it anywhere until the end of the month but hopefully I can get it sorted out then. Y'all are the best.

HunterTheBeagle 07-07-2013 04:17 AM

2 Attachment(s)
OK so we were not drilling tonight so I had a chance to take apart my licence plate to get to my mount. Hoping that I would be able to see where I may have messed up. No such luck it looks like its in the correct order to my noobie eyes. Like I said earlier I won't be able to go to a cb shop until the end of the month so I thought in the mean time I would tinker with it and try to figure it out on my own. Here are some crappy cell phone pics maybe one of y'all with some experience will see something I don't

Attachment 269840



Attachment 269840


Also, I just read that your suppose to check swr in an open area, I have been checking about 100 ft from a drill rig... my bad, but I feel like I should still be below 3 if everything is hooked up correct. Thanks everybody.

Neral22 07-07-2013 08:34 AM

Where you have the coax hooked, from what I understand, wouldnt the rubber all the way around the coax connector prevent the hot vs ground? I'm a newb, so Im just guessing from my understanding. May try flipping it just for grins and giggles?? I assume the mount is directly in the tub, is it touching bare metal vs painted metal?

HunterTheBeagle 07-07-2013 05:18 PM

Awesome I will try flipping it over, and yes its mounted to the tub, to bare metal, and big have a separate ground wire ran off of it and to a bolt on the strike plate for my tailgate hitch. I have checked with a meter and my mount is def well grounded to the body. So I'm figuring its something else. I will flip that and see if it makes a difference. Thank you.

groovebus 07-10-2013 09:23 AM

Teraflex makes a really nice antenna mount that goes on your tires carrier. It comes with longer replacement bolts. We have been running the coax from basically the glove compartment to the gate and going along the tire carrier brake light wiring. Works pretty good and get your antenna up over the hard top.

Sinister6 07-10-2013 09:36 AM

In Australia they set their cb antennas on their front bumper about an inch above the top. If antenna misses a branch etc you know it'll also clear your roof. Thought that was pretty smart!

BlueRidgeYJ 07-10-2013 07:02 PM

Attachment 271148

Plus the flat metal is up front. ;)

HunterTheBeagle 07-11-2013 01:15 AM

Ha that's pretty sweet, personally I feel like it would drive me crazy up front. But it does make sense.

nyoungblood 07-12-2013 12:36 AM

My Jeep came with a CB installed - I have messed around with it and let it scan for activity but I never get anything. Is there a specific channel that should be used?

Jerry Bransford 07-12-2013 10:01 AM

There isn't really any specific channel, CB isn't all that popular for the everyday guy now so you may not hear anything on the channels all the time. Ch 19 is usually popular with truckers & ch 4 is a somewhat common channel for 4x4 offroad enthusiasts, but other than that, any of the 40 is fair game. If your CB has a control labeled "RF Gain", make sure it is turned up all the way. Make sure its Squelch control isn't turned up too high, that will prevent all but the strongest signals from being heard. The correct Squelch setting is just beyond the point where it silences the hissing.

Sinister6 07-12-2013 08:35 PM

Quote:

Originally Posted by nyoungblood (Post 3953314)
My Jeep came with a CB installed - I have messed around with it and let it scan for activity but I never get anything. Is there a specific channel that should be used?

I would check on with the basics first. Antenna mount, good ground, Coax is not broken, Then put the SWR meter on it!

HunterTheBeagle 08-10-2013 03:01 AM

2 Attachment(s)
I figure I would update this and let everyone know what I ended up doing. I looked around and could not find a cb shop close enough to drive to so I decided to figure it out on my own. I checked continuity on everything I could think of and could not find anything wrong ( checking off the chart posted earlier). So I decided to shoot cooltech an email and see what they had to say.

First of all I have to give cooltech some props for being a great company they emailed be back and said they would be happy to send me whatever I wanted to try. I decided to give the gate mount a try and order another cable and stud setup. I ordered a Wilson cable, firestik stud, and 3ft firestik 2 (I thought the 4ft would be a bit tall for my taste). Hooked it all up and took it to an open field to test my swr. Set it to channel 20 and keyed the mic. My swr read 1.1 :). Checked channel 1 and it was at like 1.2 and channel 40 was at 1.3. Which seemed great to me. In addition to my swr being good it was a clear night and I was picking up skip from upstate new York (I was in central PA). Overall I am happy with my new setup and hope maybe my trial and error will be able to help someone else. Here are some pics.

Attachment 284046



Attachment 284047

Knuckles65 08-10-2013 07:19 AM

Glad you got it sorted out!

I've been looking to change my mount from tailgate (Have a TeraFlex mount at the spare tire carrier) to a license plate mount.

With the lift (2.5") on my Rubi and a 3 foot Firestik, it won't fit in the garage. I'm running a 2 foot Firestik but that barely clears the roof. I figure with the license plate mount, I "might" be able to run my 3 foot Firestik and squeeze it into the garage.

Do you want to part with your license plate mount? If so, shoot me a PM and let's see if we can work something out.

adamfitz 08-13-2013 04:08 PM

Does anyone have good bumper mounts for the antennas?

dpostman 08-23-2013 12:53 PM

Does anybody have a final height measurement of a 3ft Firestick on the stock rear tire carrier of a stock JKU Sahara or Rubi? I'm looking at this setup but my Garage doors are 8ft high and I always back into my garage and don't want to hit the top every time.

Thanks
dp

vacca foeda 08-23-2013 03:24 PM

my 3' firestick firefly on a rugged ridge spare tire mount is right at 1' over the top, so take however tall your jeep is and add a foot.

dpostman 08-23-2013 04:38 PM

That 'll work. Thanks


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