Towertalk
[Top] [All Lists]

Re: [TowerTalk] Where did 0.6 come from?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Where did 0.6 come from?
From: Pete Smith N4ZR <n4zr@contesting.com>
Date: Sun, 10 Feb 2013 10:57:21 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Recommended reading - http://k7nv.com/notebook/topics/windload.html

73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

On 2/9/2013 12:13 PM, kr2q@optimum.net wrote:
1.  I am not an engineer2.  Here is where I thought "0.6" came fromBack in the late 60's, when I was still in HS, the 
"square footage" of antennas was a hot topic.There were long discussions (in person) about "how did they get that."A 
common practice among my peers at that time was to "do the math" to extent we could.Calculating surface area was easy enough, but 
on a round surface, there is only one point(at 90 degrees) that "sees" the full impact of the wind.  As one approaches the 0 and 
180 points, well, that "point" is barely visible to the wind.Somewhere (I can't recall from where now), a simple approach was to 
use the projection of around surface (cylinder).  If you do the math, it comes out to somewhere between .6 and .66of the surface area 
(using round numbers).  I always used 2/3.I hope the table below comes out OK.But either way, if you round off to the nearest whole number, 
both work the same.And THAT is what I did, way back when.  Maybe completely unfounded.  LOL
Now, I just go by the manufacturer specs.  Probably worth checking.de Doug KR2Q


diameter 1/2 surface use 0.6 use 0.66 1 1.571 0.9 1.0 2 3.142 1.9 2.1 3 4.712 2.8 3.1 4 6.283 3.8 4.1 5 7.854 4.7 5.2


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>