Hi Tom,
Thought you'd like to hear a funny story about the original George Brown
120 radials tests.
At first it looks like a nice number, one radial every 3 degrees. However,
a few years back, Rich Rosen, K2RR was talking to the co-author of the
original article with George Brown. I think it was Bob Lewis, W2EBS (?) in
NJ, who was then active on 75 meters. He'd be pretty old now (about 92!).
Bob said something like this: "The technician finally laid down 100
radials. He came back and said, what do I do with all the extra wire still
on the reels. Bob said, just make more radials. When the reel was empty,
there were 120 radials. Guess what became the standard?"
73,
Joe, W1JR
At 08:20 PM 1/11/01 -0500, Tom Rauch wrote:
>Any time you deal with the government, the rules are secondary to
>what they want to see. What you learn to do, whether filing for type-
>acceptance or doing a BC station, is do what they expect to hear.
>If you do what they expect, you never get put through the ringer.
>
>Part 73.189 (4)
>
>"At the present development of the art, it is considered that where
>a vertical radiator is employed with its base on the ground, the
>ground system should consist of buried radial wires at least **one
>fourth wavelength long**. There shall be as **many of** these
>radials as evenly spaced as practicable and in **no event less than
>90**." (120 radials of .35 to .4 wl and spaced 3 degrees is
>considered an excellent ground...blah blah on and on)
>
>This is the text that 120 radials 1/4 wl long came from. The FCC
>just loves seeing 120 1/4 wl radials, and a ground system like that
>will slide right through their reviews without raising any questions. If
>you add a screen, even though it is only required on a voltage fed
>antenna, it will slide through even better!
>
>So to properly slide through the FCC, engineers have been
>"trained" to use an (unnecessary) screen and 120 1/4 wl or longer
>radials.
>
>If you have less than 90 1/4 wl radials, a red flag pops up and they
>make you prove it still works. If they don't see a screen, they want
>to know if the antenna is really current fed (heaven help you if the
>radiator is .3 wl tall instead of .25 wl and there is no screen). They
>act like the applicant doesn't know what he is doing, and start
>looking at everything closely. 120 radials at least 1/4 wl long and a
>screen guarantees you pass that point without having to prove
>anything, because they see "headroom" over the minimum and
>think you are a conservative fellow who makes good solder
>connections.
>
>Kinda like counting chads in Florida.
>73, Tom W8JI
>w8ji@contesting.com
>
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