Hi everyone,

I'm looking for a good antenna setup for my new CB on my 02 F-150. I don't really want a magnetic mount, but I don't know the best way to mount dual firestiks, seeing as I don't want them on my bumper and I have a soft toneau cover (also everyone suggests mounting firestiks at least 6 feet apart). Any ideas would be great. Thanks.

 

Where has everyone mounted their antennas?

 

We did an example in my electromagnetic classes quite a bit about how pointless it is to mount dual antenna at the width of a vehicle. I'd have to run the numbers again, but basially you want constructive interference between the two and not destructive, where the two signals or out of phase.

Without looking at my books or notes, I think CB is 27MHz.
300/27=36ft or ~11 meters. So it takes 11 meters to complete a cycle. So first off I think it's more important to have an antenna that is 36 ft, 18ft, or 9tf long to get a good length relation to frequency for resonates. If you use one channel more than another, then just do the simple math and make an antenna that length. The next important thing is making sure the impedances are match b/t the antenna, the cable, and the reciever. The standing wave ratio or SWR should be like 2:1 to 1:5 is alright. 1:1 is perfect power transfer.

There's a ton of stuff you can do to get better reception before even moving to dual or quad antennas (which will impact your directivity). a good read if you're into it is "The Truth About CB Antennas", William Orr, W6SAI

Really though, the days of the low power CB and the art of efficently getting long range out of them is nearly dead. Between the cell phone and the new gigaHz band you get so much range with so little work.

 

I would disagree as to how pointless. There are alot of variables your class may not have factored in. Terrain, weather, etc.

I ran a dual antenna setup on my wrecker some years back. Mounted at 70" on center and angled slightly forward when sitting still. I have been told 9' centers are optimal.

I also had dual 360 degree ground planes mounted to two 5 foot whips. I also ran a 1500 watt linear, and on a cloudy day I remember talking to a paramedic in Williamsport PA, from Montgomery, NY.

that's ALOT of miles!

 

Wilson 1000 or the 5000 is good too depends on how much power you are running as to which one to get. The dual antennas you usually can not get far enough apart on these trucks so they are actually worse preformance wise than most of the singe whip antennas. I was thinkinhg 8' was the optimal distance apart but maybe it was 9'. I would mount them on the mirrors on each side if I ran dual whips.

 

I personally just have a magnetic mount on my roof as I don't like drilling holes and I can take it off and put it in another vehicle if I need to. Most of the people I know that use them have the same antenna I do mounted on the roof also.

 

Not really that many miles. Besides being illegal, a 1500 watt amp is WAY overkill for what you're trying to do. With a simple 50 watt radio you can reach all the way across the globe into europe if the conditions are right. Once on my stock 1/2 watt CB with marginally tuned 5 foot antenna (single antenna BTW) I reached all the way from the northern oregon coast to a guy in San Diego. In most cases it's not about the watts but having the properly tuned equipment and the right propagation conditions.

 

I don't doubt that you talked to a guy in San diego that night-but you should understand that it was a total fluke. That had nothing at all to do with your radio or the way your antenna was tuned. It was 100% atmospheric. My unit is a signal unit in the Army, and you would not believe how the condition of the Earth's troposphere can effect how a radio wave travels. Any time you talk to someone on a CB that is over 10 -15 miles away, it is the weather doing that for you. CB raidio is LOS (Line of Sight) Meaning that that if you could not hypotheticaly see your reciever, the only way that he/she is going to recieve your transmission is if you get a bounce from the earth to the troposphere and back to the earth. And if you can get one bounce you may be able to get 2 or three................

 

it's nearly 200 miles. That's not bad for a $40 Cobra CB back in 1991.

As for overkill, I wasn't "trying" to do anything. The linear was 50 bucks, and the rest of the setup was paid for by the towing company. We only monitored ch's 9 and 19. I just happened to be "chatting" one night when I bumped into a female paramedic in PA.

on another note...my Mom had a touch lamp that would cycle through the brightnesses if I was using the linear in the driveway.LOL.

 

Feds3.0 gave you some pretty good advice. I have built and designed a large variety of antennas, and the best advice for CB (27mhz or 11M) mobile is a single whip, with a good ground, mounted in the center of the vehicle and use as long of whip as practicle. For max reach using LEGAL equipment nothing beats a 108 inch steel whip, but they can be rough on drive throughs. The Wilson antennas mentioned will litteraly blow away any dual fire stick you can set up. If you like the dual whip look, just run coax to one and forget about the other.

The FCC is cracking down on illegal power so watch out, not to mention you will see weird things happening to other electronics in the vacininty if you don't have a background in LOW pass filtering and fundamental overload, ok enough of that.

I too have talked around the world on 15 WATTS on 10m as a HAM using a simple dipole antenna, it is fun, but for point to point I prefer VHF. Try to find some HAM radio operators in your area, most will be happy to help you out and tune your equipment. Take the test and join in the fun.

Tim
n9xds