Cb antenna range

[blonde1boarder]

Hey guys. I'm getting a Cobra 19 Cb radio soon and I'm wondering about mounting. Majority of people on here mount on the back just under the tail light but my understanding is that that makes the antenna very directional. Ideally the antenna would be mounted on the roof. So I'm wondering about what kind of range people get when the antenna is mounted on the back. I'm considering putting mine on a hinge that folds the antenna down onto my front plate bumper for DD and I'm wondering if this will give me good enough reception for wheeling. Another option would be to mount a shorter antenna on the roof with a hinge.

On a separate note did everyone tune their own antenna or did you have a shop tune it for you?

 

[OU4x4]

i have my antenna mounted at the back near the tail light and have no issues with reception.
you just have to make sure the top one or two feet of the antenna stick up above roof line.
and i have mine mounted on a quick release to avoid garage parking problems
i have no trouble talking with people a couple of miles away

i tuned my antenna and it's easy. just order a meter with your cb and other stuff. i think i paid $20 for my meter.

 

[Gerdo]

The rear corner of a 4runner is the worst spot. The body blocks the signal and you will have less range in that direction. If you have a CB for wheeling and talking to your buds in a group, you probably won't notice.

The center of the roof gives the best ground plane and the most consistent signal pattern.

The front fenders also work well, the hood is a good GP also. All antennas should extend a foot or more above the body.

 

[blonde1boarder]

Ok here's another question for you guys. I want to avoid holes in the roof so with the roof still work as a ground plane if I have my antenna mounted to my stock roof rack? Or does the antenna actually need to be mounted to the roof?

 

[fluffeh]

If you put it on the stock roof rack and it isn't grounded, you can ground it with a wire to the body.

 

[Whitson Metalworks]

102" whip FTW!! no tuning, bumper mount and still 5' above the roof, i hear stuff from miles and miles away (faintly from 30+ miles the other night), but not everyone wants to rock the old school whip, i know i know

 

[mikebontoft]

I was gonna ask about the whip actually... just lock it down like they do on the military vehicles. I think that would be kinda cool.

 

[absalom]

I have a 4' firestik on the corner of mine, and it was tuned by a shop. My reception/transmission is awful. I definitely regret not going with a VHF unit instead. And it's true, the corner is the absolute worst place to mount.

 

[duncaterro]

The body blocks the signal and you will have less range in that direction.

 

[Whitson Metalworks]

The whip is pretty cool. I went with it since its the best functioning setup but i dig the look too. I mounted mine on a spring which helps keep it in postion and makes the whole setup the correct electrical length. It doesnt flop around and has yet to touch the truck, when i need to i tie it to the roof rack, takes two seconds.

 

[beerstash]

I had the whip on my full size Bronco, attached it to the tire carrier and spiked a tennis ball so it wouldn't beat up the top. I always had more range than anyone else with their CB's. That and I had the 29 LTD WX NW ST mounted between my seat and the center console. I wish I had the room inside the T4R to mount it.

 

[98OzarksRunner]

The roof would be the best place since it acts as a ground plane and gets the antenna as high as possible, then on the front fender would be the next best (the Aussies mount theirs on the bull bar, but use UHF radios which act a little differently).

But, given the amount of atmospheric noise (and idiot noise - read 'ham radio snobbery' here) and limited range of CB it probably doesn't matter much. You'll be lucky to get 5 to 10 miles of reliable communication range with a CB (sometimes 2-3 is doing well!) so I just use mine as a trail rig to talk to other drivers, which is normally within 1/2 a mile (and mine is mounted on the rear bumper). If you want range, get a ham license and go 2 meter (VHF) FM - hit a repeater at 30 miles with a few watts, and no noise.

And, as a technical matter, the reason to mount the antenna as high as possible is not because the vehicle shields the antenna in certain directions (placement has some effect on HF transmission but it is due to the 'ground plane' effect of the car, not the metal blocking the signal). It is to provide a good ground plane, and more importantly, the closer to the ground the antenna is, the more ground losses you will have, due to increased radiation resistance (the technical stuff). The 102" whip antennas is the best option since it doesn't use a loading coil (which also increases radiation resistance).

Here's a pretty good link for CB antenna basics: http://signalengineering.com/ultimate/mobile_antennas.html

 

[OU4x4]

Not trying to start a fight with everyone but the rear corner works fine as a mount location.
as long as you have some antenna above the roof line.
there are a ton of guys here that use the same location and have no trouble
I understand it's not the technically perfect spot but since most of us aren't trying to talk to the space station, it works fine.
and it's easier than drilling holes in the roof!

 

[RatFink]

The roof would be the best place since it acts as a ground plane and gets the antenna as high as possible, then on the front fender would be the next best (the Aussies mount theirs on the bull bar, but use UHF radios which act a little differently).

But, given the amount of atmospheric noise (and idiot noise - read 'ham radio snobbery' here) and limited range of CB it probably doesn't matter much. You'll be lucky to get 5 to 10 miles of reliable communication range with a CB (sometimes 2-3 is doing well!) so I just use mine as a trail rig to talk to other drivers, which is normally within 1/2 a mile (and mine is mounted on the rear bumper). If you want range, get a ham license and go 2 meter (VHF) FM - hit a repeater at 30 miles with a few watts, and no noise.

And, as a technical matter, the reason to mount the antenna as high as possible is not because the vehicle shields the antenna in certain directions (placement has some effect on HF transmission but it is due to the 'ground plane' effect of the car, not the metal blocking the signal). It is to provide a good ground plane, and more importantly, the closer to the ground the antenna is, the more ground losses you will have, due to increased radiation resistance (the technical stuff). The 102" whip antennas is the best option since it doesn't use a loading coil (which also increases radiation resistance).

Here's a pretty good link for CB antenna basics: Signalengineering.com

any life in this old thread!

quick question: The highest position for an antenna would be on my tailgate in the fully open position. It would be about 6 inches taller than the roof, so would it be possible to position the antenna on the hatch so that it could utilize the roof as a ground plane; limited in that the only usable space for a ground plane is only 180 degrees. Or could tilt/position my 102"antenna to bounce them off my roof to provide a better ground plane?
:shrug: