[TowerTalk] yagi comments

Frank T. Brady ftbrady@cosmoslink.net
Fri, 13 Jun 1997 14:23:15 -0700


So --

 Maybe Mike at M2 wasn't so wrong when he said that a 4 element on a
gain-optimized boom had about as much gain as one could realistically obtain
in practice?

 .2 and .25 spacing of a 20m 4 element array gives boom lengths of around 40
and 50 feet respectively.

 The same spacings for a 20m 6 element array gives booms of 66 and 82 feet.

 Since 60 feet is about the largest boom usually used, could it be that the
6 element monsters aren't really giving enough extra gain to justify the
significant mechanical problems that go with them?

 I sure would like to see someone actually verify the 10 or 11 dbd gain
claims for some of these big monobanders.

Best regards and 73s,
 Frank - W0ECS


>On 6/13/97 9:57 AM, Charles H. Harpole at harpole@pegasus.cc.ucf.edu 
>wrote:
>
>>Physics still says, I think, that more elements, properly placed, equal
>>more gain.  Could I, and physics, be wrong?  K4VUD
>
>The NBS (now NIST) studies of a couple of decades ago decisively showed 
>that the BOOM LENGTH was the primary factor in determining yagi gain, and 
>that the number of elements had surprisingly little to do with it. 
>(Although there were some very interesting exceptions)
>
>
>
>Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@radio.org
>Quote: "Not in a thousand years will man ever fly!"
>            -- Wilbur Wright, 1901
>
>
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