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Mobile New 102” Whip & 4” Spring - Trimmed SWR

Discussion in 'CB Antennas' started by AndrewGS, Apr 21, 2018.

  1. AndrewGS

    AndrewGS Sandbagger

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    I got a new stainless steel 102” whip and 4” spring. My mount gives about a 2” rise, so there’s about 108” of antenna. I checked SWR today and it’s not too bad, but I figured I could do a little better. Here are my readings:

    With 4” Spring
    CH 1 - 1.4
    CH 20 - 1.6
    CH 40 - 1.8

    Without 4” Spring
    CH 1 - 1.3
    CH 20 - 1.4
    CH 40 - 1.5

    I trimmed 5-3/8" off the top and that put the SWR at 1.4 across the band with the spring. I'll have to wait until my new DX-94HP arrives to see how broadbanded it is. I think that's acceptable.

    I also ordered a corona ball since I cut the little stock one off when I trimmed it.

    IMG_0783.jpg

    Here are a couple of pics of my mounting. And yes, it's properly bonded for ground plane.

    IMG_0779.jpg

    IMG_0778.jpg


     
    Robb and binrat like this.

  2. AndrewGS

    AndrewGS Sandbagger

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    Sorry, wrong corona ball.

    IMG_0784.jpg
     
  3. AndrewGS

    AndrewGS Sandbagger

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    OK, so I put it on an analyzer this morning.

    IMG_0791.jpg IMG_0792.jpg IMG_0793.jpg IMG_0794.jpg IMG_0795.jpg IMG_0796.jpg IMG_0797.jpg

    Looks like my PRO520XL and MFJ meter served me well. lol

    IMG_0781.jpg
     
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  4. undertaker

    undertaker Undertaker

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    Looks good..
     
  5. Robb

    Robb Yup

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    V. Good.
     
  6. camaro1

    camaro1 Well-Known Member

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    personally I think I would have taken the spring out instead of cutting the whip down,, your going to need to tie the whip to something with the spring on there its going to be flopping all over the place when you get on the highway
     
  7. Mudfoot

    Mudfoot Sr. Member

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    ...or get a beefier spring.
     
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  8. AndrewGS

    AndrewGS Sandbagger

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    It's a heavy-duty ass stainless spring. It'll keep the whip from bending if it hits something but on the highway it's rigid. Only the upper third of the whip bends back a little on the highway.
     
  9. Mudfoot

    Mudfoot Sr. Member

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    Have you checked impedance while driving at highway speeds?
     
  10. AndrewGS

    AndrewGS Sandbagger

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    Not yet. I'll have to do that this week.
     
  11. 357magnum

    357magnum Well-Known Member

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    And they say no texting and driving ? I hope you are using cruise control .:D:ROFLMAO:
     
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  12. AndrewGS

    AndrewGS Sandbagger

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    Sitting in the driveway.

    2B495560-E9E0-41EB-B2ED-893D62D55AFA.jpeg

    At 75MPH.

    874640F6-EAC4-436A-9694-DBA2669E65FF.jpeg
     
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  13. AndrewGS

    AndrewGS Sandbagger

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    OK, got my corona ball in today and installed it. Had to trim a bit more off the whip as expected, but I think I've got it set in the sweet spot now.

    IMG_0834.jpg
    IMG_0835.jpg
    IMG_0836.jpg
    IMG_0837.jpg
    IMG_0838.jpg
     
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