[TowerTalk] self-supporting rohn 25g??
Joe Subich, W4TV
w4tv at subich.com
Tue May 9 14:15:17 EDT 2006
Because you are in an area where icing can occur, Rohn 25 would
not be self supporting at 40 feet. In icing conditions the
wind load rating for a 70 MPH region is 2.5 square feet at 30
feet and no antenna at 40 feet.
You would need Rohn 55 to have any capacity at 40' with icing.
These numbers come from the chart in my old Rohn catalog.
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of Martin
> & Ann Mein
> Sent: Monday, May 08, 2006 8:37 PM
> To: Towertalk at contesting.com
> Subject: [TowerTalk] self-supporting rohn 25g??
> Hi all,
> Can anyone tell me if it's OK to install a 40' tower, made
> from four 10-foot sections of Rohn 25G, as a self-suppoting
> tower? The antenna that wpould be on the tower is a small
> omni-directional circularly-polarized FM antenna for 95.9
> MHZ, so it is small with not much windload. How big does the
> cement base have to be? Locally, the minimum concrete order
> is 4 yards. We are located in upstate NY. 4 yards would be
> somewhere around a 4.5' X 4.5' X 5.5' foot base.
> Thanks and 73...
> Jeff KP3FT
> Spirit And Truth Christian Radio WJIH-LP 95.9
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> TowerTalk at contesting.com
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