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Re: [TowerTalk] Radials - What is the big deal?

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Subject: Re: [TowerTalk] Radials - What is the big deal?
From: "Jim Brown" <>
Date: Sat, 31 Mar 2007 13:30:36 -0700
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On Sat, 31 Mar 2007 19:24:43 +0000, Rob Atkinson, K5UJ wrote:

>"For verticlal radiators (including slopers), lay out radials if you can 
>one or more of any length and configuration.  Don't be discouraged if you 
>hear that anything less than (take your pick: 25, 50, 120 and such) will 
>useless.  Baloney,!  Try whatever you can --- even none!"

>Perpetuating this sort of "anything works" attitude only leads to more 

On the contrary. You have put your interpretation onto the QST author's 
statement, and words in his mouth. He did not say "that any number of 
radials, even a few is okay." YOU said that. Had I been writing the piece, 
I would have placed far more emphasis on their value, but that isn't the 
author's point.  

The VAST MAJORITY of hams live on tiny lots where anything approaching a 
quarter-wave radial field is a dream, and many of them give up on 
installing any sort of ground or radial system because some hams continue 
to insist that only an ideal half wave radial field is worth the trouble. 
The piece in the ARRL Antenna Book does an excellent job of addressing the 
compromises between the THEORETICALLY IDEAL and the "I can pull this off in 
my back yard." 

Is a half wave field of 120 radials better than 20 eighth wave radials? 
Sure. How much better? You would have a hard time convincing me that it's 
more than about 5 dB better, even under the worst of soil conditions. Is a 
half wave field of 120 radials practical? I've never seen one outside of 
the half dozen broadcast stations where I've worked. And I've heard a bunch 
of big signals on 80 and 160. 

On my postage-stamp sized lot in Chicago, I had next to nothing (a half 
dozen radials about 33 ft long, and that fence. Here in CA, I started with 
20 70 ft radials, and have been gradually adding more as I have time. As I 
add them, the feed point Z drops some more, and the antenna becomes more 
stable. No surprise. It probably radiates a bit more power too. That's why 
I'm adding more. But I had a lot of fun in Chicago, with next to nothing, I 
had more fun here with only the twenty. So what the QST author is saying 
is, do the best you can and call CQ. 

W4EF works some 160 contests with a wire hoisted by a balloon near the 
short of a salt lake. I don't know what he uses for radials, but I'll bet 
it isn't 120 half waves. In spite of falling short of that ideal, he still 
managed a pretty good signal in Chicago, 2,000 miles away.  

I applaud the guys who did the extensive work to compare field strength 
with a widely varying number of radials. This is a lot of work, but quite 
worthwhile. But it is also a mistake to attempt to interpolate that good 
science to ALL conditions of soil. 

A purist approach is a wonderful thing, if you can afford it. Most of us 
cannot. For at least 25 years, there has been a growing industry of those 
who extract large sums of money from audiophiles on the basis of 
pseudoscience and a purist approach to the "ideal." 


Jim Brown K9YC


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