1. In celebration of the launch of the new redesigned site, we just gave away a FREE antenna! Click Here to See Who Won!

SWR

Discussion in 'CB Antennas' started by Freightlinerbob, Mar 20, 2012.

  1. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    I just installed a new 5' Wilson FGT using a new Wilson coax, in a truckstop parking lot. I didn't have much choice in what I bought and the SWR of 3:1+ mandated that I fix something right away. Since everything was factory original and had 7 years and a million miles on it, it was probably time anyways. But back to my question. I used the SWR meter on the radio (148 GTL) to time the antenna. Is this reliable enough?


     
    #1
  2. undertaker

    undertaker Undertaker

    Joined:
    Apr 5, 2006
    Messages:
    835
    Likes Received:
    79
    NO sir it is not you need an swr meter to be sure ...
     
    #2
  3. W5LZ

    W5LZ Crotchety Old Bastard

    Joined:
    Apr 8, 2005
    Messages:
    6,834
    Likes Received:
    726
    The built-in SWR meters in most radios are not exactly the best things in the world. The only way I know to find out if yours is reliable is to compare it to the readings you get from an average external SWR meter. That should give you some idea of how 'good' your internal meter is.
    Not a very definitive answer, huh? Nope, but it's about all you can do.
    - 'Doc
     
    #3
  4. RatsoW8

    RatsoW8 Supporting Member

    Joined:
    Nov 3, 2009
    Messages:
    2,100
    Likes Received:
    601
    For a parking lot installation YES the meter on the Cobra will get you in the ballpark until you can put an SWR meter on it.
     
    #4
    1 person likes this.
  5. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    OK, thanks. Now I have another question.

    While messing with the SWR, I could only get it down to 1.6 & 1.9. So I figured that it was going to have to do. Then before cleaning up, I decided to put some nickel anti seize on the stud. I then cleaned up and had dinner. Afterwards I checked it again because I was disappointed in the original readings. Well, I was surprised to find an SWR of 1.1-1.2! ish. ( it's a small meter & hard to read).

    So, did the anti seize make a better contact and give me a better SWR? Or was there another factor like a nearby truck moving away?

    Thanks.
     
    #5
  6. W5LZ

    W5LZ Crotchety Old Bastard

    Joined:
    Apr 8, 2005
    Messages:
    6,834
    Likes Received:
    726
    If that anti-seize stuff made any difference then the connection was really, really bad to start with. I sort of doubt that. I would have to suspect that the surroundings changed, trucks moving, whatever, had more to do with it. Then again, that's just a guess.
    - 'Doc
     
    #6
  7. hotrod

    hotrod Well-Known Member

    Joined:
    Feb 16, 2007
    Messages:
    2,089
    Likes Received:
    116
    well my guess would be the nearby trucks in your case. make sure ya close your doors when doing this.i know if im rushing i sometimes forget to do this.also check around the truckstops
    and find a cheap swr meter. they,ll be fine just for checking swr. for power thier junk.
    and they,ll tuck away nicely while your driving.1.1 -1.5 is good for those antennas.
    now tell us more details about your install
    1,single or duals
    2. lenth 2ft 3 ft ect
    3 where did ya mount them
    ive ran these on my pick ups years ago had good luck with them. just stay BELOW thier power handling capability a little
     
    #7
  8. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    Just a single antenna. 18' of pre packaged Wilson Coax. Mounted on the stock Freightliner driver side mirror mount. It's on a Mid Roof XT Columbia. The mount is at 102" so with the 5' antenna it's right at 13'6". I don't know what power the radio makes, I bought it from Canyon Radio in Canyonville OR about 1991. All I know that he sold his radios
    tuned.
     
    #8
  9. mackmobile43

    mackmobile43 Jock Supporter

    Joined:
    Feb 11, 2008
    Messages:
    6,715
    Likes Received:
    362
    Single exhaust or duals and if single is the antenna mounted on the same side, oh and where are the exhaust in proximity to the antenna?
     
    #9
  10. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    Stack is about 12' high behind the sleeper on the passenger side. I also pull a flat deck do there isn't much getting in the way of the antenna.
     
    #10
  11. mackmobile43

    mackmobile43 Jock Supporter

    Joined:
    Feb 11, 2008
    Messages:
    6,715
    Likes Received:
    362
    Then you're as good as you're going to get in this situation so just do all your checks in an open lot with a reliable swr/power meter and trust in rf theory.
     
    #11
  12. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    So can I hook up a Texas Star 350 to this set up? I have one from 20 years ago, hardly used.
     
    #12
  13. mackmobile43

    mackmobile43 Jock Supporter

    Joined:
    Feb 11, 2008
    Messages:
    6,715
    Likes Received:
    362
    If you're confident of your last readings and the antenna is rated for that much power then knock yourself out.
     
    #13
  14. Freightlinerbob

    Freightlinerbob Member

    Joined:
    Mar 20, 2012
    Messages:
    83
    Likes Received:
    4
    So what do I do with the little ground (?) wire since I didn't use it to achieve an acceptable SWR?
     
    #14
  15. Robb

    Robb Yup

    Joined:
    Dec 18, 2008
    Messages:
    8,151
    Likes Received:
    994
    ???
    Ground it to your antenna bracket and re-test the SWR.
    That is what I did with my 4 ft Wilson Silver Load.
    Surprised you didn't do that in the first place!
     
    #15

Share This Page