CB antenna Tech Question

[Romer]

I have a 4 ft fiberglas antenna for my CB mounted on the back of my 40. I installed it to high and it hits my garage door and is getting pretty wacked. I know the right thing to do is to lower it, that leaves me with extra holes.

What I am wondering is if I cut two inched off the end of the antenna, would that hurt the wavelength caharcteristics enogh to be a problem. Then I ould not have to drill extra holes. I'm a digital guy, RF and Wavelengths ins't my fortay.

Ken

 

[Chef BoyarDEE]

just a thought, but you could always sell that one and buy a 3' antenna.

 

[Dave E]

Yep. They do make shorter antennas though. There are diff legnths that end up being a multiple of the wavelegnth. Just trimming it may cause it to miss the multiple, and power will be reflected back from the antenna into the CB causing the output transisters to over heat. You can shorten it effectivly if you get a SWR meter and use it when you adjust your legnth. A SWR meter measures the power transmitted from the antenna verses the power sent to the antenna from the CB. A 1:1 reading is perfect. I think you can get by with a 1:4 for a while.

Another otption I saw was Mr Manny had filled in his old CB antenna hole with JB weld and a small filler plug of sheet steel. It worked out pretty well.


Hope this helps.

Dave

 

[Stone]

An SWR of 1.0 rarely exists outside the laboratory. Anything 1.5 and below is considered very efficient. I would agree that you need to just go out and buy a shorter antenna...maybe a baseloaded one rather than trimming that much off of your current one. You can easily get a 5/8 wave antenna in a 3' length, and it will be good enough for trail use. I went with a baseloaded steel whip with mine.

 

[Alz Toy]

Just an idea, but would putting a heavy duty spring at the base of the whip help any? That way when you pull into your garage it would give some, or you could have a bracket/something to hold it in a position that it wouldn't hit going into the garage. Seems like the easiest/cheapest solution to me. Al

 

[Romer]

Nothing like taking a break, drinking a beer and smoking a stoogie to help be creative. I stood there looking at it and I figured out if I flipped the bracket that holds the antenna 180 deg, I would get the two inches

Thanks for your suggestions guys. Now it clears the garage door (barely).

Sometimes the answer is right in front of you. You have to step back to see it.

 

[Dave E]

And cheap too!!

 

[TonkaC]

Now just raise the cruiser a couple inches and you'll be able to go through it all again

Chris

 

[Romer]

I was thinking of lowering the garage floor

 

[roscoFJ73]

Do you guys still use the 27 meg frequency, or do you use UHF?

 

[Outback]

I have CB, FRS/GMRS, 2m/70cm VHF/UHF setups. I prefer to use 2m when there are others around. But we all end up using CB on the trails. I think we should all go to FRS for trail use. Clearer and has more range than CB for the trail. CB's need to fade away quietly and let FM transmissions take over.

Jody. KE5CCC

 

[Lashcat]

Just a ? about your set up. Did you by chance have your rig checked to see if your antenna is located in the best place for to achieve the best performance. You may not need that long of a whip.