I was watching some videos from 2014 Moab Easter Jeep Safari, and noticed quite a few JK's with the CB antenna mounted on the *front* bumper, toward the passenger side. Is there some reason folks prefer this over mounting it to the rear of the jeep (bumper, spare tire carrier, tub, whatever) ? Just wondering.

 

Speaking in terms of function only, I don't know exactly why someone would mount it to the front bumper.

The antenna whip is actually only 1/2 of the whole antenna. The other half of the antenna is the vehicle it is mounted to. It works best when mounted to a large, flat surface. The only large, flat surface on a Jeep is the hood. Best results would come from mounting the antenna smack in the middle of the hood but that's kind of ridiculous. Maybe they are playing off this a little bit by mounting close to the hood.

Mounting the antenna to the right front would make RF a bit directional to the rear left.

Luckily, we usually only need to talk to the guy in front of us on the trail so performance isn't a huge deal. I have been able to make contacts throughout the eastern US using my ham radio in my Jeep but it was difficult. Mobile performance kind of sucks. I can do a lot better by just stringing an antenna up into a tree if I need that kind of comms. I decided on the rear bumper mount because it made the most sense, even if there is some RF loss.

 

There is good logic to mounting on the front bumper, but hard to tell if that was the actual motivation for the drivers of those rigs you observed. Mounting at the front avoids near field propagation problems from the rear vehicle structure and accessories such as hi-lift jacks, spare tires, tops (if any) and roll cages. Any place where the antenna runs in parallel with body panels or any other materials is bad for antenna efficiency and makes for a higher (potentially) VSWR.

The bad side is, the antenna is closer to the electrical noise generated by the engine. Best to avoid mounting to either bumper and mount as high on the body as possible. In my opinion, the best location (functionally) is on the front fender, about 6-8 inches in front of the windshield. Gets the antenna as high as possible with as little body interference as possible and still has access to what little ground plane is available. Using the correct mount, between hood and fender, eliminates unwanted holes in body panels and absolutely assures a "good ground".

Phil

 

Like already mentioned the front of the Jeep is a better location for functional purposes (also known as propagation) but it's hard to say if that was the motivation for recreational CB users. I have an antenna farm (place for up to six antennas) on my driver side front side of the Jeep. While one of those is for CB the rest is for HAM radio!

 

most bumpers built by Australian companies have the antenna mount built in the front bumper and most bumpers built by American companies have the antenna mount on the rear bumper.