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CB Radio Installation

2/18/2017

13 Comments

 
So the next thing up on the mods list was a CB. Our club has a requirement for CB radios during group events and trail runs, and while I'm not entirely sure yet that the Grand will replace the TJ on those easier runs, it's still important for me to have it. I've been planning to take the amateur exam and eventually installing a 2m/440 system in the truck, but haven't gotten around to that yet. For now, a few miles of coms is all I need on a regular basis. For better or worse, there's not a ton of information on CB installs in the WK2 models. A handful of photos here and there of antenna mounts, and a bit of HAM installs, but I figured I'd go ahead and of a more detailed write-up for anyone else that may need it in the future. 

In order to maintain a clean look for the cabin, and to occupy as little floorspace as possible, I chose the Cobra 75WX unit. The system is pretty much contained in the mic itself, with scan and weather functions, and has a separate box that converts the PL-259 coax to the mic cable, also adding an external speaker 1/8" jack (the 75WX is known for a weak speaker, since it's contained in the microphone itself... for now, it'll be fine, but I'll eventually put a speaker under one of the seats for a little more oomph). I also chose a 2' antenna with the approximate knowledge that when mounted on a spring by the bracket, I would get the top of the antenna about 8" over the roofline. While this isn't fantastic for any antenna, it will give me adequate reception and will still maintain a clean OEM+ look (it'll also be able to fit in the lower bay of my garage if ever the need arose, and I can easily swap in a taller antenna for trips with the club.

From the images I found on google, it seems most people rivet or velcro a mic clip into the center console or on either side of the 8.4" screen, but I wanted something that was a little more easily accessible and didn't require drilling a hole in the dash or the tacky look of an adhesive. I started searching for a cell phone type mount specific to the Grand Cherokee, and discovered the ProClip Console Mount which was designed to mate up to the center console by the cup holders. They provide a small tool to pop up the console and get the lip of the clip underneath for secure mounting. It took all of 2 minutes to get this thing hooked up, including drilling out and screwing in the mic clip that Cobra provided with the CB
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Photos of other owners who have tailgate mounted antennas on the WK2 have shown them in two locations, 1 being drilled into the brake light assembly, and the other into the lower bumper below the brake light. In both instances the antenna is mounted into plastic, so I went ahead and ordered a NGP (no ground plane) antenna from Firestik. This is a special kind of antenna where the internal wiring is designed to work at locations that do not have metal ground planes, like motorhome fiberglass, on a motorcycle where the metal is minimal, and on boats. In this instance it worked perfectly for my plastic brake light.

I initially was hesitating to drill into the brake light itself but after removing the plastic pop rivets and taking the light off the Jeep, I realized that there was plenty of room to get a metal bracket on the back side of the mount in between the tail light's plastic. I cut up a small piece (1.5" x 1.5" , if that) of 18 gauge steel to provide a firm backing to the antenna bracket. Drilling it out to the same hole pattern as the bracket I was then able to use the self-tapping screws to get through the mount, plastic brake light, and metal on the other side. I painted the metal plate and put it front of my heat gun to speed up the drying. Putting this back onto the Jeep I was able to close the tail gate and check that there were no clearance issues between the two when it closed. Initially there was a little bit of rubbing (against the tail gate side plastic, not metal thankfully!) so I took the bracket to my angle grinder with a flapper disc and smoothed it down a bit to cut down on rubbing.
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Next up in the process was figuring out how to get the coax cable back to the CB itself. I had decided from the beginning that the CB controller box would live under the battery compartment lid (the battery on the WK2 is under the passenger seat... makes 12v wiring a breeze), so the coax needed to end up there. I fed the wire through the vents in the back of the trunk, then used my interior trim tool kit to lightly bend the trim pieces and push the wiring underneath. I moved from the rear pillar to the trim piece at the very back of the trunk, then around to the passenger side. I had to unbolt the cargo tie down to lift the right side of that trim piece up, but then was able to feed the wire down along the spare tire compartment to behind the rear bench seats. Moving to the rear passenger door, I fed the coax under the door trim and then under the passenger seat bracket and into the battery compartment. It took a while to get all of this done, using patience as I was petrified of breaking a trim panel on the brand new truck, but I managed to use all 18' of the wire without any coils or major stuffing of any spare wire... all good things for signal! It's also nice that the only time the cable is exposed is the 2" between the B-pillar and the front passenger seat, and the location where it passes through the tailgate weather strip.

Once that was done, I went to check in on my buddy Rob who had been going to town with the battery compartment cover. Cobra includes a nice grommet and mount for the wire, so we decided that instead of mounting the control box on the top of the compartment cover, we'd mount it underneath. Due to where the battery lives there was a lot of room to the left side, where the control box fit perfectly. Simple crimp-on ends were easily attached to the (+) lead of the battery, and we grounded it out to the seat bracket for a good chassis ground. Drilling out the compartment cover to run the mic control cable under the seat, we then threw the grommet in there and called it good. The nice thing about this CB is that the microphone can detach from the control box so if I ever need to get it out of the way for whatever reason, it's simple to do so.

Here are the photos of the wiring (I labeled the route in red) and the under-seat bracket and wiring.
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After this it was a matter of getting the antenna assembly onto the rear bracket, and tuning it. While Firestik tunes their CB antennas from the factory, I find it's always best to re-do the tuning on the vehicle itself to find out how the environment and install have affected its signal. The yellow band at the base of the antenna in some photos is there to denote that is is a NGP antenna and will not function normally on a standard CB antenna install. Once tightened down on the bracket and the tailgate operation was tested a few times, we took the Jeep out to the end of a state park where marshlands surround the parking lot for quite a distance in every direction. This area provides an uninterrupted surrounding for the antenna to be tuned in, not affected by power lines, buildings, or other structures that can cut down on the reception and SWR readings.

After toying around with the adjustable antenna screw for a while, Rob and I were quite pleased to have the CB measure in at around 1.2 - 1.5 SWR at channels 1, 20, and 40. In my many experiences installing CBs in my Wrangler (I've used 3, 4, and 5' antennas, so I've done a bit of tuning) and installing them in dozens of friend's rigs, this was the quickest and cleanest install to SWR readings I've ever come across. I was quite pleased. I took some photos of the Jeep while we were out there, and let Rob mess around with the air suspension, dropping it into it's lowest settings (which I hadn't yet done) and raising it up to Off-Road 2 mode, it's highest setting.

After returning back to his house, packing up my stuff and leaving, he sat in the cab of his Tacoma and we did a range-test between our radios as I drove away. I knew going into this that the 2' antenna would be a limiting factor on range, but I was happy to find that I could hear him clearly and he could receive me clearly up to around 2 miles away as the crow flies. I had measured out distances from his house online beforehand to know which landmarks marked which distances. So, a few hours and about $150 and I have a solid CB set-up in the Grand, with a range that will do just fine for what I need it for. 

Hopefully this will help someone out in the future if they are doing the same thing to their WK2. 

Big thanks to Rob for helping out. Here are the final photos of it installed.


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13 Comments
Ross Hotz
1/3/2019 15:07:52

Very good post, but I am not clear on how you mounted the antenna to the tail light. Did you take it apart?

Reply
Ryan McKee link
1/4/2019 09:29:45

Hey Ross,

Sorry it wasn't clearly conveyed. I removed the tail light from the Jeep and drilled out 4 holes in the tail light's plastic (the wraparound portion, for lack of better phrasing) that matched the Firestik bracket's holes. The small metal plate pictured was put on the inside of the plastic wraparound, then the screws went through the Firestik bracket and threaded into the metal plate on the other side of the tail light's plastic, therefore affixing it to the taillight. The metal plate was installed for structural support so the plastic of the tail light didn't have to hold all that weight/torsion as the antenna moves around while driving.

Let me know if this clarifies your question!

Ryan

Reply
Jim
1/7/2019 09:31:32

Hi sorry tried you through intstagram realized i could write here. I am a novice with everything Jeep and otherwise auto mods. Can you help me with where exactly to wire the power and ground? Thank you. Love this Jeep and the mods. I have GC WK2 '15 Limited. Planning on tires and spacers soon.

Reply
Ryan McKee
1/10/2019 18:18:09

Hey Jim,

Sure! When I first installed this system I wired the CB to the posts on the battery in the compartment underneath the passenger seat. The positive terminal is inside on the left, I believe, and then I used the metal battery harness for the ground wire of the CB.

I've looked through and cant find any photos of this, and unfortunately since the Jeep is now on a dual-battery system the wiring I initially did doesn't exist anymore.

Let me know how else I can help explain, if need be!

Ryan

Reply
Jim
1/12/2019 07:51:48

Got it thank you

Reply
Jon
1/27/2019 14:30:15

Hey,
I know it's been a while since your install, however I've been watching your build on jeepgarage for sometime now. Can you tell me which model Firestik you purchased? I'm assuming you purchased the FG2-648?. Did this come with the mount and cable that you used? I have my CB, just trying to get the antenna, mount, cable and adaptor so I can finish my install. Thanks.

Reply
COL FA Duk
3/14/2019 22:47:16

Just read why you didn’t use the consol cubby but would love to know where all the photos of this style of installation are. I can’t find a one. Thx

Reply
NightFire (N5ED)
8/11/2019 23:21:39

Your antenna mounting has me a bit confused. I see that you mounted it through the plastic brake light and you mention going into metal, but it's not clear if it's the mounting bracket or the vehicle you're talking about. Is it actually grounded to metal attached to the vehicle?

What are you using as a ground plane? A firestick mounted in that position is dumping a ton of radiation into the passenger compartment and having it's range forward of the vehicle crippled. With no ground plane, total range will be crippled also

I know a lot of people just throw an antenna up and call it good, but understanding the needs of an HF antenna makes a huge difference.

To get the most out of any mobile HF station requires a lot of planning and grounding... a lot of grounding. It took me 3 days to wire my truck for VHF, UHF and SHF, it took me almost a month to wire it for HF.

For HF, I run 6 meter to 160 meter mobile. Running legal CB watts on an unmodified Galaxy, on a standard 1/4 wave metal whip CB antenna mounted to my bed rail I will consistently reach out and receive around 30 miles, SSB gets me to around 40 miles.

I only keep CB available because too many people refuse to get their amateur license, I much prefer staying on VHF or UHF, they have much better range, are clearer have a much shorter antenna, most radios, including the handhelds, can be used as repeaters and you can push over 1000 watts if you need to and they have so many frequencies to choose form to avoid interruptions

Reply
David
10/11/2019 00:50:44

I have a couple of questions:
1) What year is the jeep
2) how did you ground the radio? Did you ground to the battery or somewhere else?
3) Does this jeep have the battery sensor on the negative battery post? If you grounded it there, has it caused sensor problems?

Reply
Glen Wilcox
1/30/2020 18:58:17

Hi, I was trying to follow your install. I can't seem to find the Jeep info on how to route from the tail light area into the vent. I can't find any info on how to pull that vent panel either.
Thanks, Glen

Reply
Glen Wilcox
2/21/2020 10:34:38

I did find the answer on routing the Antenna CB cable: https://www.flickr.com/photos/2180miles/35153956894/. Great build/instructions. Thanks, Glen

Reply
Franz
4/15/2020 22:54:59

Hi Ryan,

Nice work. I'm doing a similar thing but with the bracket mounted above the tail light. I'm stumped as to how to get the antennae cable from behind the tail light into the vehicle - I can't see any reference on how you did this?

Any tips?

Reply
Seth link
12/25/2020 02:50:28

This was a llovely blog post

Reply



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