Bare or Insulated ground radials?

You would use bare copper wires to contact the earth. And, radial corrosion is a problem. A friend of mine works as a contract engineer for several small stations on the Washington coast. He discovered serious radial corrosion after the stations complained about coverage problems. In once case, the ground system was basically non-existant. A rebuild of the ground system improved their coverage dramatically.

Frank
www.easthillradio.com

I think that new radial installs are now using copper clad radials instead of regular copper. this reduces thefts of copper and corrosion problems while not losing much conductivity.

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Rev. Robert P. Chrysafis
Universal Life Ministries
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Moderator Hunterdonfree
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You would use bare copper wires to contact the earth. .

Frank
www.easthillradio.com

Actually that's not the function of a radial system. It is NOT necessary to contact the earth. In fact it's a mistake to bury the wires much lower than a fraction of an inch. Insulated or un-insulated does not matter. More short wires are better than a few long ones. The idea of a radial sysem is to establish the other have oif the vertical dipole and reduce ground losses which are horendous at say 1600KHZ thru 7 MHZ. i will did a a pdf file if your interested that treats this subject at length.

I stand corrected, if you're just talking about skywave and not groundwave.

Frank
www.easthillradio.com

I stand corrected, if you're just talking about skywave and not groundwave.

Frank
www.easthillradio.com

No I am talking about reducing the effects of ground losses. I posted a link to a PDF that decribes in length what I was refering too.

73, me

I read it.

Frank
www.easthillradio.com

I read it.

Frank
www.easthillradio.com

Also, not beat a dead horse but, if your ground is very lossy liike what we have here in Florida, burying the wires makes the function of the "image" even harder because the radio system is working thru lossy ground. The best situation is directly on top of the ground surface. Look at FCC test sites where they use a ground mat to "establish ground in relationship with the antenna." It's on the surface. Ground rods driven deep are good for lightning.

Better yet, think of the vertical antenna as 2 plates of a capacitor. The top "vertical" is big and round as a result of the near field and the 8 foot ground rod is.......an 8 foot ground rod.

Hope this helps...and Have Fun!

Since replying to the original post turned up no topic header, I assume it's somewhere in the archives. At any rate, the followup posts seem to indicate that whether or not the radials are insulated seems to be of little or no consequence in returning the signal to ground. E.g., if radials are buried an inch or so, I can't see that bare wire in contact with the Earth at such a shallow depth would matter at all, and vinyl would perhaps do a much better job of reducing corrosion...meaning, if true, the radials would be serviceable significantly longer. So, is there anyone in the group using insulated wire for ground radials?...And, if so, what has the experience shown?

Note: Putting down radials is. at least to my mind, a fairly laborious job, and a lot less fun than designing and building other parts of the antenna system, such as an efficient low-loss tuneable loading coil. Consequently, I feel I must do as much research as necessary (and learn lots of other things in that process) to avoid building out a ground system that doesn't work like I want.

Also, what are the repercussions of simply looping a single wire, widened sufficiently from its other half at its outer limit, as a set of 2, back to base...as opposed to laying out 2 separate wires?

TIA...

I can't answer your last question, but on the subject of radials, one quicker way to lay lots of radials is to use ladder line - you'll get 2 radials per wire layed.

There appear to be almost as many opinions on radials as there are on elevated grounds.  But from what I've read and experienced, it's just as effective (and much easier) to lay insulated radials on top of your lawn (staked down, of course, so you don't trip over them) - eventually, they'll get covered over eventually anyway.

to my question now that I have a few years experience is that a radial system using insulated wire buried about 2" works fine.

Neil

Yes, when I laid 2 insulated copper radials on the ground, pointing in opposite directions, it made the AMT5000 signal open up for many blocks in the direction the radials pointed (south and north), as well as improved east west propagation.

Also, what are the repercussions of simply looping a single wire, widened sufficiently from its other half at its outer limit, as a set of 2, back to base...as opposed to laying out 2 separate wires?

NEC4 studies of a base-driven, 3m monopole on 1650 kHz driven against a pair of separate, 5m-long horizontal radial wires spaced 2 degrees apart and buried in 5 mS/m earth show no difference in system performance compared to when those same radials are connected together at their far ends.

For best system performance, buried radials need to be distributed at equal azimuth intervals in the circular area of earth surrounding the base of a monopole.  This is needed in order to minimize the path length through the earth that the r-f currents present there due to radiation by the monopole can enter the buried wires, to be conducted back to the "ground" terminal of the transmit/antenna system with the least loss.

Yeah Carl, you don't remember me telling you that? 🙂

I probably remembered it then but I don't remember then now.