help needed

[Bill Coleman]

On 6/6/01 11:15 AM, Bill Coleman at aa4lr at ARRL.NET wrote:

>>they are good to 50' self supporting.
>
>Not according to Rohn. If you look in the catalog, they are only
>self-supporting to about 40 feet, and then only with an extremely small
>antenna load, and in the slightest winds (70 MPH).

Today I have access to my Rohn catalog.

At 70 mph, Rohn 25 can support 1.5 projected (round) square feet of
antenna in a self-supporting installation.

Rohn 25 can't even support ITSELF at 50 feet unguyed in 70 mph winds.

>Frankly, I wouldn't climb more than 30 feet of unguyed Rohn 25.
>
>>As a guyed tower, one set of guys
>>at the 25' level is sufficient.
>
>Not according to Rohn. It depends on the size of the load and the winds
>involved.

For a 50 foot installation, Rohn recommends two sets of guys, at 23 and
45 feet. This installation can support 17.5 projected (round) square feet
of antenna.

For a 40 foot installation, Rohn recommends one setof guys at 35 feet.
This can support 18.4 projected (round) square feet of antenna.



Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901

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