Telescoping dipole. No coil, 1 Coil, 2 coils?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by AD0ZO, Dec 3, 2017.

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  1. AD0ZO

    AD0ZO Ham Member QRZ Page

    Hi,

    I've been looking at 3 different portable dipoles: The buddipole, the MFJ-2289, and the MFJ-2299.

    The buddipole uses 2 coils, one for each whip. The MFJ-2289 uses one coil. I don't understand why. Can anyone explain it to me?

    Could the MFJ-2289 be setup like a giant buddipole? Would it use two coils like the buddipole, or one like the MFJ-2289?

    MFJ-2299:
    http://www.mfjenterprises.com/Product.php?productid=MFJ-2299
    [​IMG]

    MFJ-2289:
    http://www.mfjenterprises.com/Product.php?productid=MFJ-2289
    [​IMG]

    Buddipole:
    http://www.buddipole.com/buddipole.html
    [​IMG]
    [​IMG]
     
  2. AD0ZO

    AD0ZO Ham Member QRZ Page

    Buddipole:
    buddipole_2268_809320.jpg


    Buddipole:
    InJapan.JPG

    MFJ-2289:
    MFJ-2289.jpg


    MFJ-2289
    MFJ-2299.jpg
     
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    None of these solutions are efficient, but "everything works."

    The MFJ "one coil" solution may make it easier to adjust and cheaper to manufacture, but results in an unbalanced dipole. The Buddipole 2-coil solution is more balanced, but is more expensive to make and more complicated to adjust.

    I'd think it all depends what you're trying to accomplish.
     
  4. N4UFO

    N4UFO Ham Member QRZ Page

    Look at the specs... the MFJ-2299 is 20M through 6M ONLY... while the other MFJ and the Buddipole are 40m through 6m. BUT the MFJ-2299 is a full size 1/2 wave dipole (adjustable through it's telescoping whips), so very efficient compared and the best choice if you can handle the size (32 feet) and don't need 30 or 40m.

    The Buddipole is only 16 feet long and depends on the two coils for tuning most of the bands. The MFJ-2289 is over TWICE as long at 34 feet and uses that one coil when tuning up on 30 & 40m. By the looks of it, it has some way of matching as an off center fed antenna on 30 & 40m using the one coil to make the OVERALL length tune to the appropriate band. But bottom line, a greater element size and less use of inductance makes the MFJ-2289 theoretically MORE efficient than the Buddipole. (except maybe on 6 & 10m)

    In short, there are a whole lot of Buddipoles in use and seem to be well recommended. But the MFJ antennas are FULL SIZE on 20-6m and the MFJ-2289 doesn't rely on loading coils nearly as much as the Buddipole meaning both of the MFJ antennas would be MORE efficient.


    I am currently experimenting with a portable mag loop antenna system... an MFJ-935B tuner and some 1/4 copper tubing coils I made. If I decide that it just doesn't cut the mustard, I'm looking at the MFJ-2289 as an alternative for situations where I have 'plenty of room'. Because it sure isn't an antenna you'd want to try setting up in a small space like a picnic area, balcony, etc.

    STANDARD DISCLAIMER: Others may disagree, your mileage may vary, no warranty expressed or implied and batteries not included. :)

    73 & GL, Kevin N4UFO
     
    WA7ARK likes this.
  5. N4UFO

    N4UFO Ham Member QRZ Page

    Yes, old thread... just had to laugh at myself. I recently sold the MFJ-935B (especially since I have an MFJ-1786 in storage, not playing with it) and a for sale ad for the MFJ-2289 caught my eye. I thought, 'Huh. I think I've seen that before...' Then I decided to do some online research... first MFJ website, the manual, some Youtube videos and the QRZ search. And you guessed it, I find this. My own estimation and former research from 3.5 years ago that I completely forgot about.

    And BTW, I never got a whole Buddipole, but I do have a Buddistick Deluxe package in my closet I've never even tried out. (Took it in a trade.) Funny how all these things seem to keep rotating around each other.

    Looks like... my mileage DID vary! :rolleyes:o_O:D
     
  6. KC3RAA

    KC3RAA XML Subscriber QRZ Page

    I probably shouldn't be posting this here,, but if you ever decide to sell the Buddistick deluxe setup, let me know
     

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