experience with AMAloop AMA41/Mazzoni Stealth loop ?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by PA3HGT, May 26, 2019.

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  1. PA3HGT

    PA3HGT Ham Member QRZ Page

    Hello all,

    I look for HAM's who have experience with the AMAloop (DK5SZ design) AMA41 or the Mazzoni Stealth loop.
    Thanks in advance,

    Hans,PA3HGT
     
  2. VA3VF

    VA3VF Ham Member QRZ Page

    I saw a couple of their loops in Xenia. Unless they have other models, not displayed there, there was nothing stealthy about them. One was higher than myself.:)
     
  3. NH7RO

    NH7RO Ham Member QRZ Page

    Good luck in your quest for hands-on experiences regarding either of these commercially-built STLs here. I believe there is ONE ham that has taken or is expecting to take delivery on a Mazzoni Stealth Loop that has posted questions in this forum; I suggest you search QRZ for Ciro Mazzoni or Stealth Loop and see what comes up.

    Both the AMA and Ciro's creations appear to be very finely constructed and some models can handle 500-800 watts (others 100-200)---but for the money I would build a copper loop with a heavy duty vacuum variable tuning capacitor instead---and come out ahead in both costs and performance assuming I use the best possible construction methods.

    One drawback that I see with the Stealth Loop is its hinged connection point and relatively thin aluminum in part (although it is a very cool design that could be called one's "kinetic sculpture yard art" easily.

    STLs are a great way to go if one has antenna restrictions and I wish you luck in finding out more about the ones you are considering.

    73,

    Jeff
     
  4. K7GQ

    K7GQ Subscriber QRZ Page

    Hallo Hans

    I have the AMA-41 from Wimo and have used it for several years from a location in Northern Italy. It is constructed very well, yet with my particular situation, it does not perform to its full potential. From the image, you can easily see the difficulty. In this situation, I can not reduce the SWR much below 3.5:1 but the internal antenna tuner is able to complete the matching requirements. I regret that I can not mount it in more favorable location but am still able to make a number of FT8 Q's within the EU.
     

    Attached Files:

  5. NH7RO

    NH7RO Ham Member QRZ Page

    Just a thought here; what about rigging up some sort of "swing arm mount" that could extend your loop out over beyond the metal railing when in use, then swinging back in when QRT? I bet you you could tune it to resonance that way since STLs tend to couple to their surroundings in close proximity.
     
  6. K7GQ

    K7GQ Subscriber QRZ Page

    That's a great idea but possibly hard to implement here. On the other hand, I can easily see mounting a mast to another piece of the terrace rail which is at a right angle to that in the photo, and U-bolt clamping a mast to it. I could get it away far enough to be more effective. Thanks for tweaking my brain!
     
  7. NH7RO

    NH7RO Ham Member QRZ Page

    Glad the food for thought I provided whetted your appetite for an installation change; the sight of that fine antenna languishing atop the railing and the thought of a 3.5>1 "best" SWR prompted me to think, "What would I do in that situation?" (I can run 600 watts through my own STLs as long as they're below 1.8>1; otherwise my solid-state amp shuts down)

    Let us know how it works out for you, please and good luck in getting it improved.

    Ciao-73,

    Jeff
     
  8. VE7BPB

    VE7BPB Ham Member QRZ Page

    I can't tell from the picture what your height above ground is, but you might consider flipping the antenna to a horizontal position for a test. I have one of my loops horizontal at about 30 ft. above ground and it works remarkably well worldwide on 30m.

    regards, Roy
     
    NH7RO likes this.
  9. PA3HGT

    PA3HGT Ham Member QRZ Page

    Thanks all for reply ;-)
     
    NH7RO likes this.
  10. NH7RO

    NH7RO Ham Member QRZ Page

    I've never tried doing this myself but I know some loop users mount theirs at a 45-degree angle off a high balcony to good effect. A lot depends on actual height above ground that way (especially if horizontal) as the "half-wave length above ground rule" kicks in. Always worth a try if your up high, too.

    73 & have fun experimenting,

    Jeff
     

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