General Tech CB Radio Antenna Tuning

[spacecase]

ok so i bought my first CB radio over the weekend. i got it mounted and wired up but i'm worried about tuning.

i've been reading up on the subject but am having a hard time finding good articles.

from what i've read i need to test SWR reading over the full bandwidth.

is there anywhere you guys know of i can take it to have it tested and tuned? i tried searching for shops but all i get is radio shack. :-\

 

[blznnp]

Its actually really easy to do it. Just watch a you tube video of someone tuning it with a swr meter. Really easy, just want to find somewhere away from buildings an power lines to do it. I have a set meter if you want to borrow it.

 

[dbach]

4wparts can do it but you can buy a swr meter for what they charge

 

[spacecase]

they just run inline between the radio and the antenna?

does cable length or placement of the meter matter when tuning?

 

[sLcREX]

I think you wanna run 15 ft to 20ft of coax and run it away from the major mechanical areas I think like the engine bay or transmission tunnel. If you wire up your hot wire directly to the battery I think that will reduce your engine interference coming in through the radio vs if you wire it off of an accessory or ignition/fuse.

I think you can check Channel 1 and Channel 40 and have them both be under 2.0 or as close to it as possible and then you are set. That's what I gathered though, there could be more to it but that made sense to me. I havent tuned mine either so whenever you want to I could join you or help.

 

[moab_cj5]

Firestick.com has some great info on tuning. You want to get as close to 1.0 as possible (i am about 1.8 on channel 20). If you pickup a SWR meter, it will have instructions on how to use it. I bought mine from radio shack for about $30. You are welcome to borrow mine as well. It isn't too hard to tune unless you have a short in your coax.

 

[Hickey]

http://youtu.be/jRWKZskxcs0

 

[spacecase]

i've got my power ran to the battery and grounded to the side of the engine bay near the battery.

i've always been told run the least amount of wire possible for sound equipment so i installed the antenna with a 9ft coax cable.

most things i've read/watched so far are suggesting 18ft, which is double what i need. anyone else running shorter cables with good results?

blznnp, can i borrow your meter tonight? i'm heading to moab after work tomorrow so i need to get this thing tuned tonight whether i borrow or buy.

thanx for the info guys.

 

[Jinx]

i've got my power ran to the battery and grounded to the side of the engine bay near the battery.

i've always been told run the least amount of wire possible for sound equipment so i installed the antenna with a 9ft coax cable.

most things i've read/watched so far are suggesting 18ft, which is double what i need. anyone else running shorter cables with good results?

blznnp, can i borrow your meter tonight? i'm heading to moab after work tomorrow so i need to get this thing tuned tonight whether i borrow or buy.

thanx for the info guys.

I want to say the 18ft thing has to do with the wave length that the CB operate on. Realistically, buy a 18ft coax if your 9ft sucks, swap in the 18ft.

Also it seems like it needs to be in 3 ft increments because the metric meter that this world is run on.

For what its worth, I definitely don't need as much coax as I have but my CB works great (it is Coiled under my dash out of the way, which brings up a second important thing, for some reason it is better to coil extra coax vs just bunching it together.

hopes this helps!

 

[sLcREX]

You want your ground to be as short as possible, so if your CB is in your dash you would ideally want to ground it to something on the firewall or a bolt to the floor panel. But you want to strip away the paint where you are grounding for best results. So it wouldn't make sense running 6ft of ground cable when it could be 10 inches.

I have heard of the 3ft increments as well, but my understanding was that you wanna extend the wire out instead of keeping it bunched up. But maybe that's just if its bunched vs coiled.

 

[spacecase]

yeah, i read something that said coil it in a large 12" section and zip tie it in the center to keep it together.

i'll see how she tunes with the 9' cable and if i have issues, i guess i'll be buying the 18'.

also just noticed that the antenna doesnt have a ground wire coming off of it and i'm not sure what the mount is made out of but its not magnetic. kinda looks like maybe aluminum. its a firestik II, should i run a ground wire to the metal antenna holder that it screws into?

 

[spacecase]

You want your ground to be as short as possible, so if your CB is in your dash you would ideally want to ground it to something on the firewall or a bolt to the floor panel. But you want to strip away the paint where you are grounding for best results. So it wouldn't make sense running 6ft of ground cable when it could be 10 inches.

thanx, i'll prob cut it down and ground it under the stereo somewhere

also, what is the reason behind the shorter ground?

 

[sLcREX]

You don't have to worry about the ground on the antenna. The mount or clam that you will be using is what makes the ground to the chassis. The one I used before was also aluminum and it worked perfectly fine. I did sand down to bare metal where I mounted it though. Then I sprayed rustoleum around the area to prevent rust.

As far as shortest ground wire from the CB, that's just what I picked up online when I installed mine in the past, I guess the longer your wires, the more interference you can get from your engine into your feed. But I'm no pro, just speakin from what I did and read.

I use a magnetic mount antenna now though, and that works perfectly fine for my trail use. I just stick it on top when I'm on a trail and keep it in the rig when around town.

 

[blznnp]

Casey, let me know what time works good for you. I should have brought my meter with me and just dropped it off at Jack-It for you. I am at school right now and will be for a little bit. I am out in West jordan off 7800S and right next to Hwy-111. I can text you my address or I could probably meet up with you somewhere later on.

I had a short ground for mine and had real bad engine noise, my power wire wasn't running along much in the way of power wire. Switched to RG-8 or RG-6, which ever I could get at lowes (which wasn't the one that was recommended by other people) and it works great, no engine noise.

 

[spacecase]

I'll be at work till 5 if you'll be up this way. If not i'll hit u up after work.

Thanx, i'll try to tune it without the ground wire and see what happens.