CB antenna through roof - is it practical? (1 Viewer)

[John E Davies]

It looks like there are only two places on my LX450 where I could mount a CB antenna on the roof - just forward of the sunroof and at mid-roof behind the sunroof "bulge".

I think the forward location would theoretically work fine, since the hood would extend the roof ground plane. It would also get it clear of my Yakima bars and (infrequent) roof cargo. Running the coax ought to be easy down through the right A pillar. The sunroof controls and wire harness will probably limit room in there.

The rear location would have a better natural ground plane but it puts the antenna in the middle of my crossbars and I wouldn't be able to fold it flat. Running the coax would be a bigger job.

I really don't know about access and running the coax to either spot. Can anyone who has had their headliner down comment on ease of access and room for the through-roof mount stud requiring 5/8 inch clearance?

Here's the type of mount I am contemplating:

My plan was to use my existing 36 inch Firestick. Right now it's is on my Slee tire carrier and it just does NOT work there, other than to receive weather reports ;(

Thanks very much.

John Davies
Spokane WA

 

[Proven]

So you are comtemplating drilling a hole in your roof to mount an antenna?

Why not just use a magnetic based antenna in the center of your roof? I have a wilson 1000 that when not connected to my truck doubles as my stereo antenna with some special radio shack pieces screwed on the end.
link to wilson 1000

If you are headset on doing the drilling I would be aware of just how much thread will be exposed below the roofline, sealing the roofline with silicon (preferably something from like 3m 5200 which is a marine grade adhesive sealing silicon), and making a backing plate to help spread the roof flex when the whip was in the wind.

I'd think you are going to need to have a lot of space above the headliner for the wire to arc after coupling with the antenna mount, and enough thread there to properly secure it to the roof. You also have to contend with just how much of a PAIN getting access to the roof is going to be. Removing the headliner is not for the faint of heart (they cost 1,200 dollars accroding to Cdan).

My advice is to get a magnetic base and be done. How often do you use your antenna?

 

[NaterGator]

I will warn you I stuffed my hardwire Valentine One kit up in the US Driver's side headline just forward/to the left of the sunroof/map light stuff and the fit was obscenely tight. I dont know how in the world you could get enough room up in there without completely removing your headliner, and even then, if I had a hard time fitting a bit of phone cord and a small plastic bit, you're gonna have a hell of a time drilling and fitting an antenna. I would steer clear my friend.

 

[dfmorse]

John;
I've done something similar, lots of planning required. The headliner at the B pillar was chosen because of ease of removal. Also the flatness of the roof at that point and the space between headliner and inside roof. I used a feed thru connector with a star washer on the inside of vehicle and homemade washer combo on outside. The inside has a right angle N connector for RG58 or RG316 cable. This will easily support an 11m antenna; although I use it for RF feed to the antenna system; which I can remove and seal at will.

Really good grounding is the key to getting antenna systems to work on the FZJ80.

See:

http://homepage.mac.com/dfmorse/RigProj/page15.html

...

 

[alia176]

John,

I also recommend using a NMO mount that comes with a thin coax (attached from the factory). The thin coax is attached to the mount so that it's low profile under the roof and can easily be fished in the headliner space. A CB shop will have this style of mount and the antenna and definitely a HAM store. This mount is low profile and is popular among the cop and emerg vehicle roof mounted antennas. I think you end up drilling a 5/8" hole through the roof and the mount is water tight.

Good luck.

 

[John E Davies]

So you are comtemplating drilling a hole in your roof to mount an antenna?

Why not just use a magnetic based antenna in the center of your roof?

Yes to the first, No to the second:
http://www.firestik.com/Tech_Docs/MAG-MNT.htm

"Magnetic mounts should always be treated as a temporary solution to an immediate or short-term communications need. If you don’t plan to use your CB on a regular basis, don’t want to drill holes in your vehicle for permanent mounts, or don’t expect the maximum performance from your equipment, than a magnetic mount may be all you need. But remember, in spite of their convenience, a magnetic mount antenna will rarely meet the performance that is realized from a properly installed permanent antenna."

I don't plan on useing the CB often, but when I do I want to get everythiing it is capable of giving me. That's also why I want to put it on the roof. There is a ton of excellent info in those tech pages, if you have an hour to read it.

John Davies
Spokane WA

 

[John E Davies]

I will warn you I stuffed my hardwire Valentine One kit up in the US Driver's side headline just forward/to the left of the sunroof/map light stuff and the fit was obscenely tight. I dont know how in the world you could get enough room up in there without completely removing your headliner, and even then, if I had a hard time fitting a bit of phone cord and a small plastic bit, you're gonna have a hell of a time drilling and fitting an antenna. I would steer clear my friend.

The stud mount I was contemplating only needs 5/8 inch vertical room. I know the area over the driver's side is real tight, but I can't recall how much room is there dead center, for the antenna, and on the right side for running the coax. Here's the connection drawng:

Drilling the hole is a 15 second piece of cake with a short 3/4 inch Unibit (step-bit).

The BIG problem happens when you discover the hole is in the wrong place I guess I will pull down the center console for a look see tomorrow.....

John

 

[Pete483]

Theoretically there might be some minute advantage to putting it in the middle of the roof, but I wouldn't worry about ground plane that much. I have my CB drilled through the drivers side of the factory bumper and was able to get a 1.2 SWR and good range out of the thing. If you are dead set on putting this thing on the roof, good luck.

 

[John E Davies]

John;
I've done something similar, lots of planning required. The headliner at the B pillar was chosen because of ease of removal. Also the flatness of the roof at that point and the space between headliner and inside roof. I used a feed thru connector with a star washer on the inside of vehicle and homemade washer combo on outside. The inside has a right angle N connector for RG58 or RG316 cable. This will easily support an 11m antenna; although I use it for RF feed to the antenna system; which I can remove and seal at will.

Really good grounding is the key to getting antenna systems to work on the FZJ80.

See:

http://homepage.mac.com/dfmorse/RigProj/page15.html

...

Thanks. The center of the roof is my second choice due to my other roof "stuff", but I guess it wouldn't be too bad to do, compared to the windshield area.

How thick is the sheet metal on an 80? Do I need a backing plate for a 3 ft Firestik if I have a spring base? I rarely encounter overhead obstructions when in the boonies, and the antenna would normally be folded down or just removed when in the city.

Thanks,

John Davies
Spokane WA

 

[John E Davies]

Theoretically there might be some minute advantage to putting it in the middle of the roof, but I wouldn't worry about ground plane that much. I have my CB drilled through the drivers side of the factory bumper and was able to get a 1.2 SWR and good range out of the thing. If you are dead set on putting this thing on the roof, good luck.

I don't agree that the advantage is minute, but there are certainly lots of other factors in deciding where to put the durn thing. Drilling holes is a pretty big factor.

How long is your antenna, and which bumper? I really don't want anything over 4 or 5 ft, so that rules out the back bumper, and I don't want it at the front of the truck, so what's left is the roof. I already tried the tire carrier and that doesn't work worth a flip. It would be fine there if it was a long stainless whip.

I appreciate all the inputs. Don't think I'm arguing with them.... I'm just thinking out loud.

Jon Davies
Spokane WA

 

[Slomo]

FWIW I mounted my Radiall/Larson in the roof behind the sunroof and have excellent reception and pretty much the optimal ground plane with CB and 2 meter. I don't use roof racks so the location is not an issue for me but when the whip/coil is not on it has a cap that only sticks up 1/2". This link shows the install and has some pictures and part numbers if interested. The antenna mount has about the same space requirements at 5/8".

Good Luck

 

[FT4WD80S]

The roof is a great place to mount antennas, but I'm too scared to drill holes up there. So I opted for a mount on the luggage rack and gutter mount, not optimal but it works.

I saw this bracket mount that attaches to the rear of the car from an Aussie website. Not bad coz' it's elevated a little, looks sturdy enough to handle big antennas like the 102 inch steel whip. I got excited so I contacted the mfr...but theres a few problem they are only available for the right hand side and shipping is way tooo expensive. If only..... somebody can make it here in the good ol' US of A I would want one made for the left and maybe for the right hand side too . any one with a metal fab shop???

 

[dfmorse]

Thanks. The center of the roof is my second choice due to my other roof "stuff", but I guess it wouldn't be too bad to do, compared to the windshield area.

How thick is the sheet metal on an 80? Do I need a backing plate for a 3 ft Firestik if I have a spring base? I rarely encounter overhead obstructions when in the boonies, and the antenna would normally be folded down or just removed when in the city.

Sheet metal is around 1/16" and I doubt that u will need a backing plate. I would use a star washer instead of the pictured lock washer. U want good grounding at this point in the antenna system. The star washer 'bites' into the metal, giving a good ground. The step drill is the right way to do the drilling; really nice clean hole. NMO style roof connectors are great, my buddy has them all over the roof, so thats another option. Removing the overhead switch/lighting will give access in this area with out removing the head liner, and, if not mistaken, there is lots of room (vertically) for the coax. Use some rags below the drilling area to catch metal bits.

 

[sleeoffroad]

John, on my first truck I put a Wilson 1000 through the roof. Works excellent, you can remove it and use the supplied cap to close the threaded socket that it screws to. The inside of the mount is made for roof installs and is really flush mount. On my truck was on the rear 1/2 of the roof. If you drop the headliner, you will see there is actually a spot where there is no padding. Can't recall if you remove a cutout or if it already gone. The mount is well made with gasket and seals and never leaked.

The roof is plenty strong. I even drove it into the garage once with the antenna on top. Bent the antenna and buckled the roof a little, didn't even lak after that. Use a step drill as recommended and secure the cables well to avoid ratlled. Use duct tape to stick it to the roof.

You can see it here

On this one I had a 2m atenna on the roof and CB on the tire carrier. Shows roughly where that spot is

 

[John E Davies]

I looked again above the sunroof control console, and while I "think" I could squeeze a small diameter mount in there, it would be off-center and there just isn't any extra room for the cable.

Thanks especially to Slomo and Christo for their info - I think I will get a different roof antenna (from my present too-short Firestik) and mount it in the back of the roof like on their trucks. Inside access doesn't seem too bad, esp if I can do most of it through the courtesy light opening.....

Slomo - from your write-up it sure sounds like you know what you are doing. I want this antenna for emergency use in the boonies, and to use when driving on logging roads in the Idaho mountains to check for truck traffic, NOT for organised trail rides, so length isn't critical. However I have to be able to stow it inside the truck, so that is big one factor. What do you recommend for an antenna for max performance? I know a 102 inch steel whip is best - will it be ok in the roof or is that too much leverage and how could I ever stow it? What would be second best to the 102? Christo is recommending the Wilson 1000, and that sure seems like a good choice. Any comments on that?

How about quick disconnects for the whip itself - any recommendations on what to buy or avoid? It would be easier to stow a bulky base-loaded model like the Wilson if I could unsnap the whip, but will that screw up the SWR too much? (I do have a test meter.)

Thanks very much for the assistance, and I'll post pics, probably when the weather turns better.

John Davies
Spokane WA

 

[Safado]

John,

I have a Wilson 1000 mounted in the center just behind the 2nd row dome light. The cable runs easily up the B-pilar and the mount is just as Christo described with a nice cap for quick connections. Never leaked even with 2 feet of snow on top. The ground plane in that position is excelent and the SWR is right on. I get phenominal range with it and have been very happy with the setup. The whip itself can be removed from the base with 2 set screws, but that will alter you SWR as that's how it's adjusted. But you could just mark the correct spot on the wire and return it back to the same spot every time...wouldn't be hard at all. Good Luck

 

[tclndcrz]

i would not drill through your roof for a cb antenna. you will only decrease the value of the truck and open up another area for rust to begin.

I used a mount that looked just like yours. my first time offroading with the cb antenna the hinge part snapped off just from the antenna wagging back and forth

 

[Slomo]

I want this antenna for emergency use in the boonies, and to use when driving on logging roads in the Idaho mountains to check for truck traffic, NOT for organised trail rides, so length isn't critical. However I have to be able to stow it inside the truck, so that is big one factor. What do you recommend for an antenna for max performance? I know a 102 inch steel whip is best - will it be ok in the roof or is that too much leverage and how could I ever stow it? What would be second best to the 102? Christo is recommending the Wilson 1000, and that sure seems like a good choice. Any comments on that?

How about quick disconnects for the whip itself - any recommendations on what to buy or avoid? It would be easier to stow a bulky base-loaded model like the Wilson if I could unsnap the whip, but will that screw up the SWR too much? (I do have a test meter.)

Sorry I don't have pictures of the antenna parts not installed, but the NMO mount attaches to the roof with a star shaped base that digs into the metal and gets a very good ground. The small black cap in the picture on the thread screws on with a rubber gasket that seals to the roof and keeps water out. You unscrew that to screw on the whip/coil assembly with your hands, no tools. 6 years on two trucks and I have not had any rust or leaks. I keep the cap on and the coil/whip assembly in the truck to throw on whenever I need it. The whip is cut to length to tune it and is about 49" for mine which is manageable to stow without too much hassle, having the whip tuned and the proper length will determine the distance you get with your radio. I have one antenna for the CB and another for the 2 meter. Velcro straps to hold them in place and prevent rattles. The Wilson 1000 is a very good antenna and similar to the Radiall/Larson and both of their through the roof mounts are almost identical.

Also if you are planning to use your CB for emergency use you might consider getting some "shoes" or an amplifier to boost your signal. I don't think they are legal but if you are using it responsibly for emergency use I can't see someone giving you hassle. Feel free to PM me if you need any other specifics.

 

[SOCALFJ]

Nope Mo, Not legal. However available just like anything else. The most you can put through a Wilson 1000 is about 500 watts. I ran a 250 watt linear on my Cobra a few years back.. worked great.

Here's my Wilson 1000 setup on the 80. I went through the second row seat dome light also.

https://forum.ih8mud.com/showthread.php?t=115397

 

[John E Davies]

I really appreciate everything posted so far, but I have changed horses in mid-stream!

After four hours of scouring the Internet, I've decided to get my Ham license and a 2 meter radio setup (around 65 watts) for less than $300. Antenna mounting is FAR less critical with this band, and I just will scrap my Cobra CB and perhaps buy a cheap CB handheld if I ever have need for short distance trail talk.

I looked into Amateur Radio a couple of decades ago and it simply wasn't worth it for me. I didn't want to learn Morse or electronic theory (I have no interest in opening up any radio), and the equipment was very expen$ive. Everything is different today - the Morse and electronics knowledge requirements are gone for the basic license - so if you have any serious interest in mobile communications, it just makes sense to get a Ham Technician ticket.

One really cool option if you have a license is to use the free APRS satellite system to let your family automatically track your rig in the boonies. The APRS equipped radios are still expen$ive:

http://www.memphisamateur.com/index.asp?PageAction=VIEWPROD&ProdID=422

HOWEVER, for US$108 you can get a mini transmitter with attachable gps WAAS receiver that operates 25 hours off a 9 volt battery. I can carry this on my dirt bike so my wife can track me in real time in case I don't come home one day. That is very cool.

http://www.byonics.com/tinytrak/tt3plus.php

And maybe one day, when the Feds remove the Morse requirement, I will upgrade my Ham license and get the full-zoot dual band radio so I can send text messages to her...

John Davies
Spokane WA