To: | towertalk@contesting.com |
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Subject: | Re: [TowerTalk] Radials, contd. |
From: | "Rob Atkinson, K5UJ" <k5uj@hotmail.com> |
Date: | Thu, 02 Aug 2007 17:25:54 +0000 |
List-post: | <mailto:towertalk@contesting.com> |
If you were going to try the Y idea, it would be better to flip the Ys so
you have two radials tapering into one. Here's why--in the near field, you
have most of your return current and that is where you want more wire for
lower resistance and more current return. Farther out it is not as
critical. You could achieve this by putting down 60 1/8 lambda radials and
ending them with a circle of wire, i.e. all your radials fanning out inside
a wire circle. Then, attach 30 1/8 lambda radials to the circle to complete
the distance, one to every other of the inside 60. But, isn't this a lot of hassle for a ground system that may use almost as much wire and may or may not matter? Because you seem to be attempting a permanent, serious, and long term low band vertical effort with your 90 foot insulated tower, why not do it right all the way? I would spread the cost out by putting down 30 1/4 w/l radials, leaving space on the ring every other one, then a few years later when you can afford it, go back and fill in the spaces with another 30. 73, rob / k5uj By the way, on the subject of radials, I was in Home Depot a couple of days ago to see about renting some power tools and I discovered in their rental tool department, they had a small gas powered cable laying trencher available. if you do not want to lay your radials on the ground and let the grass grow over them, which is what I did, this little trencher might be the ticket. I don't recall what it cost to rent it for a full day--I think it was around 20 to 30 dollars. <<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>> My experience using a 3x3 foot grid as a ground screen is somewhat analogous to your "Y radial" idea. You often read that the ends of the radials must be spaced less than so many wavelengths. At 3 ft, my grid easily meets this criterion. However, I found that for proper operation, I still needed 60 radials originating at the vertical. Thus the Y radials are unlikely to work as you hoped. Rick N6RK -----Original Message----- Using both types of radials the end points are the same space at the perimeter of the radials circle. Can someone with the skills to use antenna modeling software compare: 60 Type One radials with 30 Type Two radials. In reading it seems to me that after 60 ¼ wave you get to diminishing returns. The time and money involved in going from 60 to 120 does not give a doubling of signal ? or even a 50% increase in the signal. So I guess the bottom line is, if I install 30 Type Two radials will I have the same signal as 60 Type One radials and if I add to the 30 Type Two is there a cost/signal benefit. Thanks KV4FE Jim On the Suwannee River _________________________________________________________________ Now you can see trouble?before he arrives http://newlivehotmail.com/?ocid=TXT_TAGHM_migration_HM_viral_protection_0507 _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk |
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