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Base Can you measure your I- Max 2000

Discussion in 'CB Antennas' started by AudioShockwav, Jan 6, 2020.

  1. Recon

    Recon NY 881

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    Why would you want to move the rings?


     

  2. 2315 Robert

    2315 Robert Grateful

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    Will be over a week or so. I will check 10,12 so forth now.
     
  3. 2315 Robert

    2315 Robert Grateful

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    Here are my findings. All taken on 75ft of tramflex RG8X Diamond SX20 meter and Astatic PDC1(they were the same one easier to see than the other). Texas Ranger 636f and ICOM 706 MKiiG. would have used an 857d but on am it cuts back power. 2m and 440 are as they should be. All SWR at 4 watts(or as close as I could get it).

    11m
    26.965 1.4
    27.205 1.3
    27.405 1.3

    10m
    28.300 1.25
    29.700 2.75

    12m
    24.930 2.5
    24.990 2.125

    15m
    21.275 1.4
    21.450 1.3

    17m
    18.110 4
    18.168 4

    20m
    14.225 5
    14.350 5

    Old IMAX on 11m was 1.2 on 1 1.1 on 20 and 1.2 on 40(honestly on either side of the band it barely moved). Very nice. I understand that even a dummy load will work however not very efficient. I was a March AFB last year and was getting in full quieting through my MFJ 1500W load on my QYT 8900 on 70cm. Also my Sirio 5/8 GPE27 is quite good when tuned to 40m. You have spoke and outlined this before but I am just amazed by it. You are just one more person that I am grateful for on this site. 73 KM6SIL.
     
    357 likes this.
  4. Cam Tetzlaff

    Cam Tetzlaff 006 Wisconsin

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    I have zero confidence that my rings are where they should be. They were very loose out of the box.

    If all this is true about them not being any good on 11 meter than I'd say there is a very strong case of false advertising going on with Solorcon and there could also be some heat put on the retailers who continue to sell this "24 foot" antenna.
     
    ENC Pirate likes this.
  5. techradioman

    techradioman Active Member

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    There's not a whole lot anyone can do about this.Solorcon no longer owns the company that makes the IMAX and nobody has deep pockets or enough to care about suing anyone for false advertising.The only thing to do is get one and try and if it doesn't work send back for refund, I don't see any other way really unless some sellers/ retailers are willing to measure before shipping and that I doubt they would do.
     
  6. M0GVZ

    M0GVZ Sr. Member

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    Please read this article on W8JI.com. He explains why some people find it a fantastic antenna and other people find it's terrible.
    https://www.w8ji.com/end-fed_vertical.htm#IMAX

    tl;dr Despite what people think it needs a ground plane. Because most people never install a groundplane for it if you're lucky to have the right combination of mast length and coax length it'll work great, if you don't it won't because most of the signal goes up into the air.
     
    Cam Tetzlaff likes this.
  7. KD2GOE

    KD2GOE W9WDX Amateur Radio Club Member

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    total langth of the bottom is 96" 8 feet
     
  8. Recon

    Recon NY 881

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    Being that my MAX 2000 is 24' and the VSWR is 1.3:1 on Ch.1, Ch. 20 and Ch. 40, I'm going to take the risk and spend the $77.00 and order and install the Ground Plane Kit. I misplaced the owner's manual for the MAX 2000. Should the tuning rings move up or move down to lower the VSWR?
     
  9. RT431

    RT431 In the swamp

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    Why would you want to lower your SWR? 1.3 is nothing to sneeze at.
    Besides nobody on the receiving end will notice a difference.
     
  10. Recon

    Recon NY 881

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    As a few guys have posted, the tuning rings were loose when their antennas arrived and the rings on my antenna were loose also. I tightened the rings, attached the antenna to the 40' telescopic mast and erected the antenna.
    I am OK with the 1.3:1. After the snow and cold temperatures are gone, I will retract the telescopic (push-up) mast and attach the ground plane kit and I will have the opportunity to fine tune the tuning rings, but only if I know which direction to move the rings.
     
    RT431 and Marconi like this.
  11. ENC Pirate

    ENC Pirate Ocean One Cape Hatteras

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    tunning.png
     
    S&W357 and Marconi like this.
  12. HomerBB

    HomerBB Sr. Member

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    I read it.

    Upside - good information.

    Downside - no lead on what might be a good mast length/coax length combination.

    The real scientific anchor in the article is embodied in the word luck . . .
     
    AudioShockwav likes this.
  13. Recon

    Recon NY 881

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    You are absolutely correct! If it ain't broken......don't fix it! If I wasn't going to install the Ground Plane Kit in the spring time, I sure as heck wasn't going to lower my mast and antenna just to obtain a better VSWR than what I have. Also, I don't know about anyone else, but I have been using three different radios and the VSWR on the three radios is "slightly" different. After I install the ground plane kit and move the tuning rings up 1/4 turn, I will decide on which radio will be the permanent base station radio and whatever the VSWR results will be, I'm done.
     
  14. RT431

    RT431 In the swamp

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    I had an A99 yrs ago and installed the gk and noticed NO difference in performance either tx or Rx. Only difference I did see was my wallet was lighter. o_O
     
  15. Marconi

    Marconi Usually if I can hear em' I can talk to em'.

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    IMO, the distance from the bottom of the mounting bracket at the coax connector to a small hole in the middle of the 2.25" inch brass capacitor we see in the image below is exactly 16" inches.

    With a small air gap inside and between the bottom and top PVC insulators...is where the matcher wire ends and the radiator begins across a small air gap. The radiator in the Imax seems to be floating.

    So, in order to get the radiator length as close as I could for my Eznec model...I simply subtracted this 16" inches from the overall radiator length I reported earlier.

    284.75"
    -16.00"
    ----------
    268.75"

    I used a 3" inch single segment wire for the feed point on my model so wire #2 is showing 265.5" inches instead of the 268.75. The small difference in the 268.75" and the 265.5" inches was the physical trim I made to set the match better at maximum gain.

    If you add matching to a model, the process of tuning is often very similar to working with a real antenna but as this notes the adjustments can be very small.

    [​IMG]
     

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