Optimizing my cb legally

Try to get the tallest Firestik that you can, so if you drive a tanker, you might not want a 4 or 5 foot antenna, but if you have a 13' 6" trailer, the 4 or 5 foot would be a better choice.

As for the 18' of coax, just run as much coax needed to make it from the radio to the antenna, 7 foot or 700 foot. The 18' thing is horse hockey, but that is for another thread.

 

if you are connecting to metal mirror and door and or roof are metal your in good shape if they are not you just need to clamp wire to mount and connect metal on body. as far as the antenna coax is concerned if manufacturer of antenna recommends 18 ' and this is long enough use it. thats how they engineered the antenna to work best.

 

Hopefully if it is the factory antenna mount the bracket is grounded to the frame.

Now there is a difference between RF ground and ground plane and DC ground. I preface this because purists tend to jump in here.

Since this is a company vehicle, I am sure you are not allowed to modify it?

What you can do is take a multi meter and check that the outside of the antenna mount shows a closed circuit (continuity) to the mirror brace or even the frame/chassis of the truck.

Again let me state before the purists jump in here, there is a difference between ground plane, RF ground and dc ground. But in this case the operator has no choice but to take the mount as is since he does not own the truck.

So if there is continuity, you should be ok, if not, maybe you can ask one of your fleet mechanics to run a ground strap from the mirror bracket to the chassis keeping it out of sight?

Now I think Wilson makes a "no ground" antenna and I have seen them at trucks stops, I am just not sure if they are the one that makes them. But you can try that if there is no continuity. I have never used that type of antenna.

Now, just for the heck of it, if you wish, check out this web site,

http://www.k0bg.com/ground.html

It helps you understand why we need the "ground"

If you can take a picture of the mirror bracket with your antenna that would be great.

Remember, that stock antenna and coax was purchased by Freightliner from the lowest bidder

 

Just a word of caution. If you're in a big truck...DO NOT USE A POWER MIC..... All the other end will hear is your road/truck noise. A good noise cancelling mic is what's needed along with a good antenna system. A good antenna is like good speakers is to a stereo...they make all the difference in the world. Personally, I would go with the Wilson antenna. Then a good noise cancelling mic...along with a good radio alignment. You won't need to be worried about how many watts this radio puts out as long as it's in good working order. Just have it checked out by a competent tech for proper operation and alignment. You'll be real happy with this radio. The 148 GTL is in my opinion the best CB ever put out for mobile use.

 

Well now that he knows for sure how good of radio he has, I guess I won't offer to make him a really good trade!

 

If you are a company driver (I noticed the Roehl truck in your picture), I suggest that you ask your fellow drivers what they have found that works well on your flatbed truck. Learning from their experience can increase your chances for success.
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By all means, check your SWR reading with an external SWR meter before you do anything else. High readings can provide you with valuable information as to any possible problems.
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Replacing the stock factory antennas on the truck is the easiest way to increase your cb radio performance. Personally, I would not recommend any antenna shorter than 4 foot in length. A 4 or 5 foot Firestick KW series or FS series are generally okay. The Francis 4 1/2 foot antenna works pretty well also. Before you buy an antenna at the truckstop ask around about some CB shops. Truckstops have high prices and limited choices. The CB shop will often tune the antenna that you purchased from them at no additional cost. Tuning the antenna correctly and saving you the hassle.
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If your SWR [ measured on an external SWR meter] can be lowered to 1.0 to 1.5 , you do not need to worry about the antenna ground plane or the coax cable in the truck.

 

If it's like my 148 you need to clip of change R131 to bring the Modulation up to 100% (mine only did 60% before). Set dead key for 4 watts AM (VR10). It will talk!