The AM Forum

Hello All,
I'll post this as a QSO to find out what direction and what action I'll need to take.

Wenesday night wind must have been past 60mph. My neighbor lost 6 pine trees. One was about to fall on our house.
I needs to get a WX station to monitor MaNature for wind speed and direction.

Problem:
My A3S Yagi with the 40M add-on, and possibly rotor, were hurt in last night's action.
The driven element on the Yagi is now loose on the boom. The wind can change position of this element. I KNOW I pointed the DAM antenna "broadside " to the WEST wind, so that the elements would not get the beating they did last night.
The DAM wind was so strong that it twisted the rotor so that the elements were pointing into the strong winds and caused a LOT of action/damage.

It is a reasonably high quality Yaseu rotor. I paid around $450. I'll have to go to square one and read the specs to see if I exceeded the wind loading. OR
if the winds get past 60mph $#it happens!!! I guess that's my question. :o


The last huge 60mph winds we had knocked the calibration off for the positioning of the Yagi. Not much, but this last storm was a doozy. prolly shifted everything 50 degrees rotation

All of this is on a 70 foot utility pole and a crane truck would have to be hired after the ground gets dry and hard. $500 rental for 4 hrs.

Anybody else have their antenna tested Wednesday night??

Thanks
Fred

I point the antenna into the wind

I had a gust of about 50MPH here around 5 PM. Its been averaging around 14MPH. Fred, I have had this Davis Vantage Pro Wireless for about 8 years. I've had one issue (which was last year). I sent it back for sevice and they were very helpful and the labor was cheap. Shy away from the Oregon Scientific. I've heard that they are all what they're cracked up to be.

Maximum wind gusts in my area reported by the local weather spotters to the computer weather info was 61 mph. I always turn the beams (front to back or back to front) into the wind. Since much of the time the winds sail out of the West or Northwest, I generally, at the end of beam usage for the day, return the beams to this position. I have a Xmas tree array on the tower as seen in the photo below. If you look real close, you'll see a rope that is hanging around the bottom boom that generally just drags the ground on normal use. When very high winds are coming, I pull the rope taut and tie the bottom part of the rope to the bottom of the tower. This keeps the antenna boom from swinging, and helps to prevent wear and tear on the rotor brake, especially if the wind seems to develop rotation or some other random direction even for a short period, to a minimum. The tower is designed for a max height of 75 feet.

Yaesu specs to determine possible rotator failure (Click on FAQs):
http://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=75EAFAA323C271AB4E2C8359D4450039&DivisionID=65&isArchived=0

Assuming you only had the A3S and the 40 meter add-on kit up there:
Max turning radius would be around 18 Feet
Total weight would be around 31 pounds
Using their formula for your "K" number = 18 X 31 = 558 ft-lb
Check the "K" factor on the bottom line in the link for your rotator
Based on what you said you paid for the rotator, it's either the G-800 () or the G-1000()
The PDF manual below also includes additional information on wind loading for pole mounted antennas

I don't have any idea how fast he wind was here, but it took out some trees, barns, small buildings, and the power. Also ripped the feedline off my 40 meter dipole.
Shelby KB3OUK

It hit here Wednesday.  Two power outages keep us without electricity most of the day.  The entire dead elm tree that lost a limb 3 weeks ago and took down the beverage broke off about 4 ft. from the ground and took down the beverage again.  And it was taken down twice by the ice storm, by a  fallen limb and another fallen tree.  I  have had it up for about 6 years with no problems, but in less than a month, fallen limbs and trees have taken it down 4 times.  Hope everything that can fall has fallen by now. 

The #8 copperweld never broke, but one support pole was bent, and lost a total of 5 insulators.  Replaced the uprooted guy anchor at the support pole with a bigger one and managed to force the bent pole back upright using ratchet puller.

No other damage from the wind, but the ice storm did major tree  damage.  I  have a lot of chain saw work ahead.

Pretty bad winds Thursday.  Branches all over the roads.

Power went out at work.  They sent us home early (12:30).

I did not check my crummy G5RV.  Still loads up and I worked VE1UJ (Nova Scotia) on 3725 at 630PM yesterday, so I guess it's still getting out.

No major interruptions here.  Just a short one that reset my clock radio.

We get winds like that all the time in the winter. Gusts to 60-70 MPH commonplace every year and very little damage until they get worse than that.

How come the damage is worse in the east? More trees?

I suppose in your area, everything easily prone to getting blown down or away already is.  Plus you probably build your stuff substantial enough to withstand it.

The storm that killed 9 people in Lone Grove, OK went about 3 miles South of our house.  We have a lot of debris in our area but no damage nor did the power go out.

That was one scary storm, and I have seen a lot of them.  Winds approached 65 mph here and shifted directions as the storm passed by.  We were lucky.

And more people, houses, etc.


Didn't hear you on 75 meters last night but we did have a Wyoming station check in.

71 mph gust here. and now you should know whats coming now.  :'(

took antenna down. 3rd time. just got home been out with wifey all day.

noticed the matchbox tuning strange. Goes without sayin no more trees for ant supports. The ones I have around me just cant survive windstorms.

now to go out and survey the damage with the camera.

[update] well, not bad. the actual ant is ok, the one side seems to have the support cable  pulled out of the end insulator. we can drill new hole and it will b good as new.  :D