Stupid CB in a 60 Question....

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Ok, here is the set up.
Cheapy Cobra CB with a fire stick antenna attached/grounded to my ARB bumper. I ran the power and ground to the CB directly from the battery.

The problem.
I send and come across perfectly - so the truckers say. But, when recieving there is a lot of stactic and i cant make out anything anyone is saying. I can even go to some random channel is it shows activity on my meter...I think there must be interferance in the line somewhere.

very confused....do you think my CB is fawked??
 
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Capt. Jim said:
Had the same problem with one. It was a loose connection in the mic connector. Try and wiggle the connector/mic wire and see if it might clear up.
i changed the mic out with another i had....same problem. I may just put the other CB i have in and see it is the CB itself..


thanks
 

Trunk Monkey

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I had a similar problem. I'd gotten the array of washers and plastic grommets in the wrong order for the antenna mount and it wasn't grounded from the truck. CDan was kind enough to help me out and I was good to go.
 
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FZJFillmore said:
I had a similar problem. I'd gotten the array of washers and plastic grommets in the wrong order for the antenna mount and it wasn't grounded from the truck. CDan was kind enough to help me out and I was good to go.
I am thinking if i run a ground from the fram to the antenna i might be in good shape. I will try that and if it doesnt work...i am gonna get a swr meter and try and tune it..
 

treerootCO

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Noah said:
I am thinking if i run a ground from the fram to the antenna i might be in good shape. I will try that and if it doesnt work...i am gonna get a swr meter and try and tune it..
You have to have the insulator on the antenna.
 
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BMAN

 
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Sounds to me like the antenna is grounding out. Once that's fixed you should buy an SWR meter and tune your antenna anyway. Where is the radio installed? If in your dash, make sure that the back of the radio is clear and not interfering with any metal under the dash.
 
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ok, i changed the CB out with a different one i had around. The sound quality is better, but it became very poor when i cranked the engine. Why or how is the engine causing the static?? Should i ground CB to the frame or is the battery terminal ok to use??

When you say the antenna is "grounding out" what do you mean by that and how do i fix it?

cheers
 

nuclearlemon

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Noah said:
dunno...the antenna is brand new. How can i check this insulator??
the insulator is a little plastic piece that looks like a tophat. it goes in the hole that you drilled for the antenna to bolt in. it keeps the antenna from grounding out.
 

polarweasel

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Incidentally, I don't think antennas come with that little insulator piece. It either comes with the mount you're using, or if you're using a tab on your bumper or something, you ask really nicely at the CB shop and they give you one. :)
 
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polarweasel said:
Incidentally, I don't think antennas come with that little insulator piece. It either comes with the mount you're using, or if you're using a tab on your bumper or something, you ask really nicely at the CB shop and they give you one. :)
It did come with a AL bracket to put it on the mirror of a truck. I bet that is the insulator. I put the antenna in a predrilled hole in my ARB - so i would guess it is grounding out then. I will go to my local truck stop and see what they have.
 

treerootCO

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unhook the antenna from the truck, hold it in your hand and test. If it is better, then you need to find an insulator.

The noise with the engine running will still be an issue...
 
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treerootCO said:
unhook the antenna from the truck, hold it in your hand and test. If it is better, then you need to find an insulator.

The noise with the engine running will still be an issue...
do you think the if i grounded the CB to the frame instead of the batt term it would be better - less noise??
 
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This drove me crazy for a couple of evenings so I'll see if I can help. Get a multimeter or cheapo continuity tester. And I disconnect the negative battery cable so I don't fry anything.

NOTE: none of this applies to "non-ground plane" antennas--I know nothing about them. See http://www.firestik.com/Tech_Docs.htm for excellent docs on all this, including NGP kits.

What the parts look like depends on your mount, but the antenna/mount needs to make two connections, one to ground (body, frame, battery, whatever), and one (the stud the antenna connects to) to the center conductor of the coax. And the two can't be shorted to each other. Assuming it's mounted, connect the coax to the mount (probably a coax connector....Firestick has a pretty cool "fire-ring" connecter that bolts to the bottom on the mount). Now unscrew the antenna (the whip itself) and unplug the coax from the back of the radio.

Put one proble of your tester inside the stud the whip screws into, touch the other probe to the center conductor of the coax. It should beep, flash, whatever, indicating continuity. That's good--signal can get through.

Touch the outer shell of the coax w/ one probe, touch the other to bare metal on the body. You should also have continuity--this is ground.

If it doesn't pass either of these you need to correct it--these electrical paths have to be there. I would assume your ARB is grounded, but you can test it--put one probe on bare metal on the bumper, the other on bare metal on the body--if you don't have continuity you need to run a ground wire. And bare metal means bare--paint is an insulator.

Now test btwn the center coax and the body, and btwn the outer coax shell and the inside of the stud--if you have continuity on either of these paths you have a short. That's where the little nylon/plastic insulator ( BTW, aluminum is not an insulator, it's a conductor) comes in. You have to get the mount attached to a good ground, but not let the antenna conductor touch the ground. Your mount should have come with a plastic washer insulator to keep these two circuits separate.

I mounted mine, checked all this, thought it was right, hooked up my SWR meter (Radio shack--be sure to get a coax jumper to connect the meter to your CB). I couldn't get an SWR reading below infinity. Started futzing w/ antenna length adjustment (I have an adjustable firefly), still no improvement. Started over the next night, testing ground etc, and I had a short that was screwing everything up--the little nylon washer wasn't btwn the ground and conductor the way it should be. Once I fixed that I got SWR readings from 1.2 to 1.8 (very good). BTW, if you read the docs on the firestick site you'll learn that where you mount the antenna affects SWR--the bumper may not be the best place to put it, but I would imagine it'll work. Best place from the SWR point of view is probably smack dab in the middle of your roof, but most people don't want one up there. I have satellite radio, so I put mine where the stock AM/FM used to be.

Good luck!
 
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thanks....this at least gives me a path to start. My guess is the antenna is not mounted properly, but we will soon find out...
cheers
 

BMAN

 
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Good Post Steve!

If your ARB is powder coated, which I believe they are. You're not getting a good ground plane there. Be sure that your mount is properly grounded.

The very best way to hook up your radio power and ground is directly to the battery. This should reduce the RF from all your truck accessories (i.e. Alternator, AC fan, lights, signals, etc.) altough it may not eliminate them. What model radios do you have?
 
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What did you do with your excess coax from the CB to the antenna???

Do not roll it up like a garden hose or extension cord, this creates a "choke" and causes all kinds of shizzle with your rig. Stuff any excess coax randomly and not nice and neatly rolled up in a loop. Better yet, take the LONG way getting to your radio and string out the 18 foot of coax as much as possible.

Just a suggestion for someone installing a CB for the first time. We all live and learn.

Jody.
 
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