CB Radio Antenna

Status
Not open for further replies.

CSL126

Member
Joined
Dec 19, 2002
Messages
314
Location
Tuscaloosa, Alabama
I just bought a CB antenna from a local truck stop. The antenna is actually designed to go on an 18-wheeler I think, but I found a magnetic mount for it. I know that the antenna is supposed to be mounted onto the roof of a car because it uses the car as a ground-plane, but I had to mount mine on my bumper because it was just too high up on the roof of my car. How bad will this hurt my reception? Is there any way to make some soft of artificial ground-plane out of my bumper? It's not a metal bumper, but I guess I could put some type of sheet metal or something over it..?
 

N4JNW

Member
Joined
Oct 1, 2006
Messages
766
Location
Irvine, KY
You can still use this.

With the antenna mounted on your bumper, the frame, chassis, and rest of the car will become your ground plane. You will be somewhat directional in transmission and reception however. Since it has a magnet, why not put it on your roof or trunk lid anyway?

Some truck stops DO have ground plane "kits". It consists of a small acorn style nut, with 3 or 4 radials sticking out of the sides. I've ran those before, heck I still have one, but I can't tell it does anything for me. It just made my SWR higher.

If you're using this for an actual CB, I wouldn't be as concerned about ground plane, as I would be the SWR. Although both are directly dependent on each other..

If you have the antenna mounted on a bumper that IS NOT metal, you will have a high SWR. The magnetic mount antenna ground by inductance from the magnet. So you just cant "glue" the magnet to the bumper, or anything else. It has to attract to it. I had a K40 CB antenna on my old truck, and I could CHANGE the SWR by adding and removing layers of thin plastic under the magnet.

If you want to talk, bite the bullet and stick it on your roof or trunk lid. If you're just interested in listening ONLY, you're fine the way you are. Just don't use the microphone. LOL..
 

CSL126

Member
Joined
Dec 19, 2002
Messages
314
Location
Tuscaloosa, Alabama
Actually, I have an SUV (Mercury Mountaineer). The bumper is plastic, but I mounted a piece of sheet metal onto the bumper and then placed the magmount on top of that.

I thought I was posting in the Antenna forum originally, that's my bad. Admin, if you happen to run by this post, can you please move it to the antenna forum.
 

N4JNW

Member
Joined
Oct 1, 2006
Messages
766
Location
Irvine, KY
If the bracket you made is hard mounted tot he bumper, you should have no problem. As long as you have a screw or bolt going through some metal, so the antenna can get a "good" ground, you're good to go. Set your SWR and burn it up!
 

policeMonitor

Member
Joined
Jul 15, 2005
Messages
301
Location
Michigan
there is a guy down there in alabama his handle on the radio is handyman i have talk ot him on the radio if you can find him he can realy help you, also this site will help you alot more then this one http://www.cbradioforum.com/ join this one and you will learn alot of cb radio
 

KOK5CY

Member
Joined
Jan 6, 2005
Messages
394
Location
Afton, Ok
High Swr

To get those swr's down to 1.1 flat match . The car or truck need's to be re-grounded with welding cable or in other word's 4 AWG . All car's and truck's have a factory ground cable from the body to the frame . Most cber's run a ground cable from the trunk floor to the trunk lid so the swr is at it's lowest . Truck's can run a ground from the bed to the frame ...then from the cab to the frame and so on ....my mag mount is in the middle of my tool box and it's grounded to the frame and i'm using 10 AWG wire . But if you run new ground's make sure the point's of contact's are free of rust and paint .
 
Status
Not open for further replies.
Top