Posted: 10/24/2019 11:45:50 AM EDT
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ETA - I realized I never specified the type of antennas I'm looking at - I'm looking at dual band ham radio antennas from Larsen, Diamond, and Comet.
I am new to ham radio, and am looking at installing one in my Jeep. I've been trying to figure out the most convenient place to mount an antenna. All of the antennas I'm interested in have NMO connectors and are all about 40" long. My Jeep is my daily driver, so I really don't want to have to fold the antenna down every time I come or go. Mounted on the frond hood lip/fender would be too tall to clear my garage door. Mounted on the spare tire carrier would also be too tall and might not work when the soft top is folded back (when I fold back the soft top, it goes up against/over the tire). I walked around the Jeep last night with a tape measure, and the best spot I could find is the area I refer to as "the cup holder". There is a space on the rear bumper on the driver's side between the license plate and the fender. I tend to set my coffee there when I'm loading or unloading, and have twice left travel mugs there that held on for longer than you'd think when I drove off. But I digress. I found this when looking for a place to mount in that area. On a Jeep forum, someone mounted a CB antenna this way. Molded side mount from firestik.com:  
Installed on Jeep:  
Immediate issue I see is that the mount is for CB antennas, not NMO. Was thinking an adapter like this:  Being new to all of this, I'm sure I'm missing something that would be obvious to those with more experience. I'm sure there's some reason this would not work. It just seems too easy. |
| The answer you seek is http://k0bg.com/antmount.html. A lengthy but thorough read. |
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you will probably detune it with capacitive reactance with so much of it parallel to the body
that plastic mounting area isn’t a good ground plane Attached File when i had my TJ, i mounted 90* NMO & 3/8” mounts on the left and right rear corner....vhf and cb/hf kinda like this.... Attached File |
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as stated above, you will not get any ground plane mounted to plastic.
and Most of the RF comes off the antenna at the base and less at the top. The base and some more of your antenna is below what should be the ground plane, so not only will the antenna be de-tuned being so close to the rear quarter panel of the jeep, it will be severely degraded in efficiency because the RF wll not go through the metal quarter panel of the jeep. will it work? probably Will it be degraded, absolutely. |
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Thanks for all the replies so far. I had a feeling that mounting it lower would be bad performance wise.
I'm trying to avoid making any holes in the body - it would be nice to use existing bolts, or make holes in something easily replaceable, like a turn signal or license plate frame. Quoted:
here’s a pic, right before i sold it 
https://www.AR15.Com/media/mediaFiles/2275/CD435D0A-6E3D-47BE-B4F9-E875E210FE6C_jpeg-1135990.JPG |
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Attached File https://www.ruggedradios.com/index.php?main_page=product_info&cPath=1167_1332&products_id=2165 Attached File https://www.ruggedradios.com/index.php?main_page=product_info&products_id=2759 Get a NMO antenna and one of these mounts for your Jeep. The mount is $35.00 and paired with a flexible whip NMO antenna, you won't break it or beat the crap out of your Jeep. |
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What about a bracket to spare tire mount.
https://www.amazon.com/Wrangler-Antenna-Spare-2007-2018-Unlimited/dp/B01I9K307W No extra holes 
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Quoted:
https://www.AR15.Com/media/mediaFiles/54857/JEEP-KIT-INSET-03-LG_jpg-1136013.JPG https://www.ruggedradios.com/index.php?main_page=product_info&cPath=1167_1332&products_id=2165 https://www.AR15.Com/media/mediaFiles/54857/MT-ANT-JEEP-DS-01S_jpg-1136015.JPG https://www.ruggedradios.com/index.php?main_page=product_info&products_id=2759 Get a NMO antenna and one of these mounts for your Jeep. The mount is $35.00 and paired with a flexible whip NMO antenna, you won't break it or beat the crap out of your Jeep. Quoted:
What about a bracket to spare tire mount. https://www.amazon.com/Wrangler-Antenna-Spare-2007-2018-Unlimited/dp/B01I9K307W No extra holes https://www.quadratec.com/sites/default/files/styles/product_zoomed/public/product_images/Rugged_Ridge_11503.89_CB_Antenna_Mount_Installed.jpg 
Bonus pic of why I call the area of the bumper my cup holder. That travel mug in the pic held on for over a mile before falling off. I realized I left it there right as I was getting onto the highway. Made a quick U turn and scooped it back up. 
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Quoted:
What about a bracket to spare tire mount. https://www.amazon.com/Wrangler-Antenna-Spare-2007-2018-Unlimited/dp/B01I9K307W No extra holes https://www.quadratec.com/sites/default/files/styles/product_zoomed/public/product_images/Rugged_Ridge_11503.89_CB_Antenna_Mount_Installed.jpg I had to scrape off the coating to get a ground connection, but that wasn't especially hard. The groundplane is iffy with that mount so a low- or no- ground plane type antenna works best. Been running it for 7 years with no issues whatsoever. |
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I just realized, I never specified the antenna type - I'm looking at dual band ham radio antennas. I'm leaning towards the Yaesu FT-8800R right now for a radio and looking at dual band antennas from Larsen, Diamond, and Comet.
I'll update the original post. Thanks for all of the suggestions/replies . |
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I put a 1/4 mag mount on the fender in the back
corner on the inside of our 1997 soft top, and now in our 2017 hard top 4 door. I haven't really tested them against the same antennas that are on the roof of my van & wagon, but I have never noticed any decrease in range. But I will say, I haven't talked on the radio in our 2017 yet. Link to 1/4 wave I use. No jeeps were harmed in the transmission of this message, but a few electrons were horribly inconvenienced. |
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Quoted:
i would put the mount where it is optimal for your vehicle and just use a short antenna around town that will fit in your garage, when you go boondocking you can switch to a longer antenna. no one says you only get one antenna to use. alex |
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Quoted:
i would put the mount where it is optimal for your vehicle and just use a short antenna around town that will fit in your garage, when you go boondocking you can switch to a longer antenna. no one says you only get one antenna to use. alex I can't believe that never crossed my mind. SMH. Thanks! ETA - Are there any advantages/disadvantages between mounting up front on the side of the hood/cowl like K9-Bob posted vs the spare tire mount like Mach posted? I'm leaning towards the front now because I wouldn't have to worry about the soft top being on the antenna when I fold the top down. Also, there would be a shorter cable run since I plan on mounting the radio up front somewhere. When I researched before, I saw people mention that a steel belted radial might affect performance if the antenna is mounted between the tire and the Jeep. Would this really be an issue? Also, I saw discussion somewhere against mounting up front by the driver or passenger. The discussion was about RF exposure. The radio I'm looking at is 50w/35w. Would this be a concern? |
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Quoted:
i would put the mount where it is optimal for your vehicle and just use a short antenna around town that will fit in your garage, when you go boondocking you can switch to a longer antenna. no one says you only get one antenna to use. alex great idea never thought about that before |
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When I researched before, I saw people mention that a steel belted radial might affect performance if the antenna is mounted between the tire and the Jeep. Would this really be an issue? When I put my analyzer on it, it was perfect SWR. The antenna may rub against the tire depending on its size. Performance was great. FWIW I use a Comet SBB-5NMO, but have used the much shorter B-10NMO as well. With the B-10 there was a little bit of shielding effect from the rim but it was minor. |
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Terrible place to put an antenna for VHF/UHF bands, if you want it to actually do anything.
Need to get it up on the vehicle as best as possible. A shorter and more flexible antenna would solve issues with clearance. The Sti-Co "flexi-whip" is a great little antenna if you could get it up onto the roll bar or windshield frame or something like that. If you have to go with fender-top height, the ~40" tall dual banders would be better choices. |
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This bracket and a standard NMO kit. Mount it similarly to the Firestick CJ/YJ/TJ fender mount bracket. Works adequately when paired with the Larsen NMO-2/70 for the average Jeep (mall crawler type). Don't pair it with a heavier antenna like a Comet CA-2x4SR. Good thing about this setup, it works on MB/GPW, CJ, YJ, TJ, JK, and JL.
If you need something more rugged for a stupidly heavy antenna...you could throw RR some bones but personally...RR rips a lot of people off and is shady as fuck on radio side of their business. |
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A shorter antenna with less (claimed) gain, with adequate ground plane, mounted high and away from the body panels will work a lot better than a tall, high gain antenna mounted at the location shown on your picture. Also look at Comet SBB5, 1/2 wave antenna. It will perform well with less adequate ground plane. You should be able to mount it on the hood or on the rear quarter panel (1/2 way up) with enough room to clear the garage door (assumed to be 8 ft high). Either way, try to keep the antenna away from conductive body parts. Like mentioned by others, most vertical antenna have the most RF current near the bottom. Proximity to conductive objects will reduce the antenna's performance and will cause some detuning. Ideal antenna location is at the center of the metal roof. It's not always practical but keep it as high as possible and away from body panels. Good SWR doesn't mean that the antenna is working well. A dummy load has a perfect SWR but radiates very little. |
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Thanks to everyone for the replies and suggestions. Right now I'm leaning towards the spare tire mount. That would be quick and easy, and I can figure something out to keep the folded back soft top off of the antenna. Never mind, turns out the assembly doesn't come apart to where I could put a bracket inside of it. Yeah, I'm really leaning towards the spare tire mount. |
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Quoted:
What about a bracket to spare tire mount. https://www.amazon.com/Wrangler-Antenna-Spare-2007-2018-Unlimited/dp/B01I9K307W No extra holes https://www.quadratec.com/sites/default/files/styles/product_zoomed/public/product_images/Rugged_Ridge_11503.89_CB_Antenna_Mount_Installed.jpg |
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One more thing on the rugged ridge spare tire mount I've seen done -- for those of you who are concerned about the low mount --
is to use all-thread or metal rods to elevate a small flat metal bracket for the NMO to a point above the tire. This is just a foot or 18" or so from the top of the vehicle -- and being a jeep, there's zero metal or ground plane available on the roof to either work as a mount, or to interfere with this setup. One company, Arizona Rocky Road, actually makes a mount with the elevation built in. I'd say that's a good compromise. ETA: Here's a link to a (better pick of this mount with the tire off than the web site has. |
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Quoted:
One more thing on the rugged ridge spare tire mount I've seen done -- for those of you who are concerned about the low mount -- is to use all-thread or metal rods to elevate a small flat metal bracket for the NMO to a point above the tire. This is just a foot or 18" or so from the top of the vehicle -- and being a jeep, there's zero metal or ground plane available on the roof to either work as a mount, or to interfere with this setup. One company, Arizona Rocky Road, actually makes a mount with the elevation built in. I'd say that's a good compromise. ETA: Here's a link to a (better pick of this mount with the tire off than the web site has. I'd need a shorter antenna for day to day driving around town, but it solves the issue of the soft top pushing on/over the antenna when it's folded back. ETA - I parked the Jeep with the rear right under the garage door. Looks like there is about 33 or 34 inches from the top bolt on the spare tire carrier to the bottom of the garage door when it's open. The spare tire antenna mount already places the base of the antenna an inch or two above the top bolt, so I'm looking at an antenna about 30 or 31 inches if I want to clear. Comet and Diamond both have 27" antennas with springs that may be my best option for day to day driving. If I went with the taller mount from Arizona Rocky Road, I'd probably need to drop down to an 18" antenna. |
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Just put a 1/4 wave on the lip of the hood and be done with it. 1/4 wave is only 19” or so off the hood.Attached File Use your analyzer to get the best location. |
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I'm probably being overly paranoid, but I'm leaning away from a front mount (cowl, windshield hinge, etc) and more towards a rear mount. I used the Amateur Radio RF Safety Calculator to figure out distances from the antenna for 144MHz at 50 watts and 430MHz at 35 watts. The calculator pretty much matched what I had read on other forums, 4-9 feet for 430 and 6-13 feet for 144. Right now I'm considering drilling some holes to mount to the rear passenger side, close to what KB7DX posted in this thread or what Derek45 posted above. The only issue there is that my Jeep is an '07 - the tail lights are taller, so there's not much room to mount anything above. This is why I mentioned putting a bracket inside the tail light in an earlier post. I don't think the tail lights can be disassembled, though. |
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Images from the analyzer thread.
Attached File Attached File Attached File In the pics there is an SBB-5 dual band on the windshield frame and a 102 inch SS whip on the rear. The whip is held down by the plastic wire retainer on the windshield frame as seen in one of the pics when not in use. The SBB-5 can be folded over for clearance if needed but as mentioned further up in this thread, I have a 1/4 wave 2m whip when I need clearance and don't want to stop and fold the SBB-5 down. The SBB-5 usually is only installed if I'm way out in the desert and need a little more gain. Normally the 1/4 wave whip is installed. NMO mounts for the win! One other note about the windshield frame mount I'm using. It puts a lot of stress on the mounting screws when the SBB-5 is installed being it's longer than a 1/4 wave whip. |
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Dual-band back there as others have pointed out is bad - especially if the 440 Mhz band is important. I mount my dual band off a tab that hangs out over the hood crack just forward of the battery as my best mount for a bad vehicle. Putting it out there gives it a bit of the hood for a signal ground plane. The mount is an NMO mount. It wears a cap, an 18" dual band, a 32" dual band, or a stupid long 62" long OMG the repeater isn't responding long antenna. It's really too big for that mount but it's an emergency use only thing. Around town the little 18" whip hits the repeaters. Out on the trail I pull the medium lenght antenna out from under the back seat and stow the little guy. I have a CB 3/8" stud on my Shrockwork's tire carrier and put either a 3' or 4' firestick. The 3' CB in the back and the 18" dual band on the front. 
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Here's how mine is mounted.
I did drag it under a tree branch that I thought wasn't going to clear the light bar. It just rotated the mount at the adjustment point and all I had to do is loosen up the screw and rotate it back vertical. I need to get a shorter antenna for using off road. |
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I tried that specific mount on the side of my wife's ZJ, it really sucks. The gasket is too soft and the mount will move. The impedance must be so far away from 50 ohms that the SWR will never be good and I had it drilled into sheet metal. It's still on the ZJ, no antenna, has been there for years, way before we got our tickets. Go with the other NMO style mounts others have posted. Mount it to metal only. If you just have to mount it lower, just be prepared to possibly not be heard at further distances. Back in my CB days, I mounted a Wilson 1000 on the roof of my Bronco, which was lifted. It hit all sorts of crap while on the trail, but it was a strong base-loaded antenna that took the beating without issue.
Ya know, now that I have an analyzer, I should stick an antenna on that mount again and see what the mighty fine junk box says. |