I need some help - Antenna Warning on SWR Check

Discussion in 'CB Radio Forum' started by HD_Renegade, Jun 15, 2011.

  1. HD_Renegade

    HD_Renegade Road Train Member

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    I have my new Cobra 29 LX and a Wilson 2000 antenna. This is for my PU. I have a fender mount for the antenna, and I am getting a Antenna Warning with I try to do a SWR Check. I have no idea what I am doing and I have not been around CB's in over 20 years, please help.

    Thank you
     
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  3. Rat

    Rat Road Train Member

    Is the mount properly grounded?????
     
    rabbiporkchop Thanks this.
  4. HD_Renegade

    HD_Renegade Road Train Member

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    The coax cable has a ground straight to the mount that is attached to the bolt in my front fender. Not sure how to explain the cable but normal end for the CB, an eyelet type thing for how it attaches to the antenna on the fender, the ground cable is built into the cable.

    I have thought about going to Walmart buy a cheap mag mount antenna to see if the problem goes away????
     
  5. Hardlyevr

    Hardlyevr Road Train Member

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    The bolt that holds the bracket to the fender itself may not actually have a ground. You could test it if you have a test light, with one end on the positive side of the battery (but make sure you disconnect the antenna cable 1st so it doesn't try to find a ground back thru the radio).

    Yes a mag mount may solve your problem.
     
  6. HD_Renegade

    HD_Renegade Road Train Member

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    Ok I do have a test light, just so I understand this right.

    Disconnect the antenna from the radio, run the test light from the battery (lucky for me the battery is right next to the bolt) to the bolt for the antenna mount and this will rule out the ground issue for the antenna?

    Anything else I can try too?

    Thank you
     
  7. Hardlyevr

    Hardlyevr Road Train Member

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    if you have the one end of the test light on the positive side of the battery and put the other end on the bolt on the fender and the light comes on, you know it really is grounded. No light means it isn't grounded and you will either need to figure out a way to provide a ground by creating one with a wire or ground strap, or go the mag mount route.
     
  8. Rat

    Rat Road Train Member

    Yes on hook the coax from the mount first then hook the aligator clip fromt he test light to the bracket then touch the probe of the test light to the battery. If the light lights up then your bracket is grounded. If it is not grounded then either scrap some paint away so that the bracket is touching bare metal or run a short ground wire/strap from the bracket to the closest spot in which you can get a proper ground. NOT the battery!!!!! You are looking for a chassis ground.

    Once you have a proper chassis ground then your SWR will change. You will most likely see it lower on 1 and higher on 20 and 40. I usually see about 1.5 on 1 and around 2 on 20 and 40. You then need to tune the antenna to get it as close to 1.5 as possible on 1-20-40. This means you have to lower the upper whip or possibly remove it and trim some off the bottom. Don't trim more then 1/2 inch off at a time.

    If you get to a point that it is 1.5 then you should be good to go. If it starts going the other way, were 1 is going higher then 20 and 40 then you need to raise the whip slightly. This is why you only trim 1/2 inch at a time. So that you leave enough incase you have to raise the whip.
     
  9. HD_Renegade

    HD_Renegade Road Train Member

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    Ok here is what I have, test light battery to mount light comes on, good ground.

    But when I do the same test batter to antenna shaft (lower just above the mount base, no light??? Should I have a good ground all the way to the antenna shaft???

    Thank you
     
  10. Hardlyevr

    Hardlyevr Road Train Member

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    the plug/attachment of the antenna bracket should have some kind of plastic sleeve in it to keep the center of the antenna (that is carrying your transmit power) isolated from the ground. If it is missing, cracked broken on not inserted correctly it will mess up what is supposed to happen. You should have ground at the outer ring of this connnector where the cable attaches.
     
  11. HD_Renegade

    HD_Renegade Road Train Member

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    Well just for the sake of trial and error, I bought a cheap mag mount antenna from Walmart and I still get the Antenna Warning too, and I dont seem to hear anyone talking either.
     
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