Ground Radials

Discussion in 'General Technical Questions and Answers' started by KD8HRR, Mar 11, 2008.

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  1. KD8HRR

    KD8HRR Guest

    I just bought a Hustler 5btv. I was reading the instruction manual and found the measurments for the ground radials. My question is can you coil the radials making them shorter but keeping the required length?
     
  2. KA0SOG

    KA0SOG XML Subscriber QRZ Page

    Worked for me. Coiled them on 6" PVC wrapped in double sticky tape to keep them in place. Used this on the back side against the fence. Other sides are regular length.
     
  3. AG3Y

    AG3Y Guest

    The whole idea of laying down radials is to make that first quarter wavelength of surface out from the feedpoint of the vertical as conductive as possible.

    Coiling the radial wire satisfies the electrical wavelength of the wire, but compromises the physical situation.

    You might have a fair compromise there, but nothing, I repeat, NOTHING can substitute for a field of actual quarter-wavelength radials spread out under the feedpoint of a vertical antenna.

    BTW, there have been some comments raised about elevated radials. Elevating the radials, even a few feet above the ground surface increases their effectiveness several-fold. Many have reported that as few as three or four radials at around 6-8 feet elevation work as well as 120 of them laying on or just below the surface of the ground!

    I have a 20 meter ground plane in my back yard, with three radials at about 9 feet above the ground, and the performance is not all that bad.

    YMMV, however. 73, and good luck. Jim
     
  4. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Actually, the 8 feet above ground is for the AM broadcast band at 600 kHz. By the time you get to the 80 meter band this translates to like 16 inches, on 40 meters to 8 inches, 20 meters to 4 inches, and so forth.

    Before my swimming pool was installed I had 48 buried radials under my HyTower and it worked very well. After the pool was installed (they dug up a good number of my radials when digging the hole) I went to elevated radials that run along my wood stockade fence, around the retaining wall for the pool, and around the foundation of the house. With 4 radials cut for 80, 4 radials cut for 40, and 4 of "random" length, the HyTower performs much better than it did with 48 buried radials. These radials are anywhere between 1 foot and 6 feet above ground, do not run in a straight line, and so forth.

    Glen, K9STH
     
  5. K8JD

    K8JD Ham Member QRZ Page

    One of my summer projects is elevating my Butternut 6-band vertical and what I can salvage of the present radial system will be elevated about 8 ft up. This height should prevent strangulation of the kids who shortcut through my yard to get to the woods behind my house, preventing lawsuits (it is illegal to hang trespassers in this county)...
     
  6. AG3Y

    AG3Y Guest

    The only reason I suggest 6-8 feet, Glen is because it could get to be a bit hairy trying to work around some radials that are only 8 to 16 inches off the ground ! I mean, try mowing the grass, or even just walking around in a back yard with a bunch of wires at a height that can trip you ! Yes, I can imagine that fewer radials would work at less then 2 feet above the ground, but it certainly would be hazardous navigating !

    73, Jim
     
  7. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    No problem if you run them along a fence, foundation of your house, retaining walls, etc. Running them elevated in a large field, etc., definitely presents all sorts of problems with the physical height above ground.

    Glen, K9STH
     
  8. N6YG

    N6YG Ham Member QRZ Page

    It's nice to see someone who agrees.. I'm a big fan of elevated radials. But every time I bring it up I'm told that a ground mounted vertical with 60 radials or so will perform better.. BULL Elevated radials are much more effective then buried or on the ground radials. When I first got my 5BTV it was mounted on the roof with just 2 tuned radials per band, It performed great. I move it to the ground as an experiment I've installed over 120 radials and it still does not perform anywhere near as good.

    The worst part about it, Was the work it was a lot more work burying all those radials then it ever was roof mounting the antenna.. When I did the math I about fell out of my chair.. I have over 8000 feet of wire buried. I have so much work into that antenna I don't have the heart to move it.
     
    Last edited: Mar 12, 2008
  9. N8YX

    N8YX Ham Member QRZ Page

    Both of the 'BTV' verticals I've owned over the years have used elevated radials - 2-4 per band - and both have worked like gangbusters. The feedpoints were placed at 30-35ft AGL and the radials sloped away at 45-degree angles.
     
  10. N6YG

    N6YG Ham Member QRZ Page

    The only thing I don't like about having it up that high is it's more difficult to lower it before a storm. Do you have the actual antenna guyed at all ?? I know when the wind starts blowing that hustler really starts swaying.
     
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