Wind and Beam Suggestions Please

[LightFoot]

Were expecting 50 mph Gust of winds out here on the San Francisco Coastal Area And was wondering would you point your beam Directly at the wind or would you turn it sideways? Im sure this is going to be interesting. Thanks and Best wishes and regards. LightFoot Off the coast of San Fran with the Golden Wave..............

 

[kevin IB/379 Stringbean]

Into the wind,not sideways.

 

[LightFoot]

Thank you kevin IB/379 Stringbean. I hear different things but I think thats the way to do it..................Appreciate your time and reply.......

 

[Henry HPSD]

Hello,

For small beams...side ways
For large beams...front.

This is due to the size wich gets blow at due to the wind.
A element is approximently 15 feet (5,5 meter)
So if the boom is 30 feet, it will be wise to put the antenna with heads up in the wind.
BUt if the boom is only 5 feet, it will be wise to put the side of the antenna in the wind.

In that way the mast will suffer the least of the forces wich are created due to the weigth of the antenna the size and the size of it.

To get deeper in it, one should calculate the entire wind "area" of a antenna (dont know if thats a good word not my native langue)
As a boom can be square of round and will often be bigger then the diamter of the elements. These are factors wich should be taken in mind.

Kind regards,

Henry
All about antennas

 

[LightFoot]

Henry HPSD Thank you . Good post. good Info..fortunately the winds did not reach its predicted Wind gusts. Best regards and thank you for the feedback..........

 

[RatsoW8]

25 years of antenna wrangling and I've never seen a yagi,in normal high wind conditions, fail from wind before the mast or tower went first. I've seen them fail from icing, a flock of tired birds using an element on a 3 element 10 meter beam as a perch and plain stupidity in the way they were mounted...but never just from wind.

I had my Force 12 C-3SS mounted on a hazer. Wind? No problem...just crank it down to the 10 foot level and I didn't have to worry about the mast bending and wrecking a $1000 yagi.

 

[GnG8d]

In that way the mast will suffer the least of the forces wich are created due to the weigth of the antenna the size of it.

25 years of antenna wrangling and I've never seen a yagi, in normal high wind conditions, fail from wind before the mast or tower went first.

You didn't read what he was saying in it's entirety.

 

[Captain Kilowatt]

25 years of antenna wrangling and I've never seen a yagi,in normal high wind conditions, fail from wind before the mast or tower went first. I've seen them fail from icing, a flock of tired birds using an element on a 3 element 10 meter beam as a perch and plain stupidity in the way they were mounted...but never just from wind.

I had my Force 12 C-3SS mounted on a hazer. Wind? No problem...just crank it down to the 10 foot level and I didn't have to worry about the mast bending and wrecking a $1000 yagi.

I have had the opposite experience. I make sure my tower and masts will handle far more than what is asked of them. My masts consist of 2 inch OD steel pipe with a 3/16 inch wall. I have had a Cushcraft A3 shear off the element/boom mounting block set screws and wear a hole in the boom from just wind. The elements then windmilled and eventually walked off the end of the boom and fell to the ground.Everything was tightened to the point of almost crushing the tubing. The antenna simply couldn't handle the winds that we get here sometimes and shook itself to death.

I do agree about the extra forces involved when ice comes into the equation however and it has also been my experience that a lot of operators ( probably most) have no idea what the wind is capable of and usually employ a less than adequate sized mast. The swaged tubing that Radio Shack sells is often used but has no place on a tower holding a yagi of any appreciable size unless the yagis is attached a foot or so above the tower bearing and certainly not when mounted five or six feet above it.

Forgot to add that I tend to agree with Henry about which way to point the beam. For years I would point the A3 into the wind but when I install the Explorer-14 with the 40m kit I may have to park it broadside to the wind because of the length of the extended driven element which will be 42 feet long.