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Radials, am I going in the right direction?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KC5MO, Feb 4, 2011.

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  1. KC5MO

    KC5MO Subscriber QRZ Page

    Hey all,
    Before I spend lots of time replacing my poor radial system I want to be sure I am going in the right direction.
    I have a Hustler 6-BTV with 80 meters ( tuned for 3.800 MHz being the lowest frequency ). I spend 90% of my operations on 40 and 20 meters both phone and the Novice CW section. I have a stamp sized yard, but I can sneek some radials outside the fence to a point. My plan is to use around 45 radials +/- at 20' and 33' due to space. I am using a square radial plate so can I set the radials in a plus shape or do they need to be placed in the common circular pattern. Any advice will be greatly appriciated because I don't wan't to make the same mistake and end up with a poor radial system again.

    Thanks
    Herb KC5MO
     
  2. W0BTU

    W0BTU Ham Member QRZ Page

  3. AA5ET

    AA5ET Ham Member QRZ Page

    You'll need less radials if they're elevated, but they need to be a close to a 1/4-wavelength for the bands you work. As soon as you bury them you'll need many more radials, but length can be shorter. Forty-five radials is great start if they're buried or laying on the ground, but you'll start to get diminishing returns at around 40. Four radials per band of elevated radials is usually enough - as long as they're elevated and cut to resonance.

    Every antenna installation is unique, and if you can't get them arranged in a circular pattern that's okay. It will probably still work fine. There's a great article in March 2010 QST about ground systems for HF verticals. You should read it and come up with your own conclusions.
     
  4. N5CEY

    N5CEY Ham Member QRZ Page

    I have a 6btv with 30 radials "in the ground" (about 1/2"), pinned every 18" or so. I have 2 radials that are 1/4 wave length on each band, 80 - thru 10 meters, plus another 18 that are 1/4 wave on 20 meters. They do NOT have to be arranged in any type of a perfect circle, nor do they have to be completely straight. You can "zig-zag" in order to fit in a given space, you can also bend around corners and objects. Naturally, a nice 360 degree circle with all nice straight lines is ideal, but you do what you can to fit in the available space. I have 37 countries and 48 states worked with my 6btv, great antenna but you MUST put the radials down to be effective.
     
  5. KH6AQ

    KH6AQ Ham Member QRZ Page

    For this vertical 20' radials will be sufficient. 45 radials is excellent and a circular pattern is best. I have a similar counterpoise on a similar antenna and the measured base-referred ground resistance is 5 ohms at 14 MHz.
     
  6. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    What you are doing is a decent compromise for the size and shape of your lot. You should try to spread the radials out as space permits since ultimately you want to cover as much area as possible. Radials that are 1/2 an inch or so under the soil work as well as radials layed on the surface so it's OK to put them under the grass.

    You also don't need to tune them since the purpose for the radial field is to provide the lowest impedance path to ground. You will probably get a barrage of comments about counterpoise and semantics and on and on but the down and dirty is that the radials provide a return path for RF current so it flows in the antenna and gets radiated and doesn't flow on the coax and wid up back at your rig. I'll Email you some good information on radial systems.

    John..
     
  7. KM1H

    KM1H Ham Member QRZ Page

    You might be better off going down to a box store and getting a couple of rolls of galvanized fencing and creating a dense network 20-30' all around the antenna. Use the type that is welded at the crosing and then hot dip galvanized. It will last many years on the ground and can easily be soldered to for attachment at the antenna or adding a few longer radials. Most of your losses will be close to the antenna and that is where you want to concentrate the ground structure. You can also buy the type that is built as mentioned and then hot dipped in plastic. It will last forever and the plastic can be removed to solder. In all cases treat the solder joints to a good cleaning and some spray anti rust paint.

    Carl
     
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