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I've installed a dual band antenna (NMO) mount in the roof. Had to install it almost at the back of the roof due to a future roof rack install. The radio is a Kenwood V71, antenna (for now) is a Comet SBB5.

I need to install another antenna for the CB, and I wanted to pop another hole in the roof and do NMO again. I'd be using a Larsen NMO27 for it. It'll be the same distance back, and 19" over to the right.

Other than the roof sloping away and making it look a bit silly, will I run into any interference issues with the mounted so close? The radios will not be used at the same time. The CB will only be for backcountry trips with guys who have no 2M radio.

One other reason I'd like to do another NMO mount, I'd like to run one of those goofy looking mobile discone for a scanner I'll be using as well. Diamond D-220 if I recall.

My other option is run coax to the front bumper and mount one of those huge whips to it for the CB. Front bumper is an 80 pound hunk of 3/16" steel with a winch.

The magnet mount is approx. where I'd mount the new NMO mount. I just tossed it up there to get an ideal of how it would look. Yes the roof looks like crap, it's getting paint soon, hence the reason to poke more holes while I can. Once the new paint is on it'll be that much more painful haha.

First gen XJ?

I'd tell you what I did with mine (which is a 2nd gen) if you want to entertain it (multi-band and CB).

Yeah, 96 XJ.

What did you do on your XJ?

Larsen NMO27 on the hood channel. 1/4 wave VHF on the roof (I ditched the roof rack for several reasons, mostly due the the drag).



Of course, I'm getting ready to redo everything and abandon the rear CA-2x4SR. As it's pictured, it has the first Anytone dual band that hit the market on the Comet, and the 1/4 wave was for an APRS tracker that was built out of a Motorola SM-50.

The strongest lobe of the polar radiation plot will be in the direction where there is the most metal in the ground plane.  So, mounting at the center rear of the roof means that the strongest signal will be radiating straight forward.    For the best averaged performance you want to put your antenna as close to the center of the roof panel as is possible.

When installing multiple antennas on different bands, just try to keep them as far apart from each other as is practical.   There's nothing you can do to change the fact that the antennas will be in each other's near fields.  So you do what you can and rely on the radios to have adequate selectivity.

That is pretty much how I understood it, just wanted to check it out with others before making it happen. Yeah I would have liked to do center roof but the roof rack prevented that. I reckon for my use it'll do just dandy.

Thanks. Gives me some ideas.

I'll be using the V71 for APRS and some local repeater usage and simplex while on the trail. I have a Mobilink and a spare phone running APRSDroid. The CB will be used in the rare occasion I'm with a group that does comms via CB.

I'm building out the XJ for that ever so popular overland stuff. Been meaning to do it for years now, finally have the means.

kinda considering drilling the F250 roof-finally have it back after a year outta service.  Part of me wants to go all in with it.  Multi-antennae on the roof and all, but then I begin to apply reality to the situ and it seems the dual-bander on the fender is really all I need (but it's so boring )

Right!? I'm worried this Jeep will end up looking like something from the NSA reject pile. I'll most likely just toss on whichever antenna I need at the time. I have a few NMO rain caps. Besides having the better ground plane, I'm liking the ease of swapping antenna that comes with NMO.

I'm wondering how a ball mount CB antenna would work in that situation.  102" whip w/ a 6" spring is 1/4 wave from what I understand and you could put a ball mount on the right rear quarter panel.

Photos here

Eh, it'll be noticeable as long as there is 1/4 wave radius around the antenna but even then it's hard to notice a difference for most users.

Mine was built as an expedition rig. I found that it cost 3 mpg to run a Yakima rack (rack came with the vehicle) and the only real purpose of the rack was to hold some lights, the jack and a spare tire carrier. To me it wasn't worth it as I also found it extremely awkward getting a 32" tire off the roof with factory Rubi wheels on it so I built a spare tire carrier for my JCR rear bumper.

Here are my specs for the build:
JCR Offroad Stage 2 front bumper (first gen)
JCR Offroad Stage 1 rear bumper (first gen, second fits 2nd gen lines better)
JCR Offroad Stage 1 sliders
Rusty's drivetrain skids
Homebrew fuel tank skid
SYE (save yourself some money on this and source from local driveline store)
Safari Snorkel (previous owner's only remaining contribution)
3.5" Rubricon Express lift (previous owner went with the 3" front, 3" AAL on flat packs, I replaced the rear leafs with 3.5" models from Rubricon Express)
1.5" Lift Shackles (done after the spare tire was moved to provide a .5" rake)
Aussie rear locker
JCR Offroad tail light housings
Goodyear Duratrec LT265/75-16E (on 16" Rubricon wheels sourced by the previous owner) which it has been wearing for 4 or 5 years now
Drivetrain is otherwise bone stock (3.55:1 gearing)

New radio plans:
Rip everything but the Cobra 25 out
Install VHF XTL5000 with W3 HHCH
Mount speaker in overhead console

Only advisory for that, you increase the chances of serious sheet metal damage if you happen to rub a tree or rock. If running a more traditional CB antenna on an XJ, I'd recommend a JCR antenna mount which mounts using the tail light housing mounts.