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 Jaybeam to Yaesu wind loading calculation 
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Post Jaybeam to Yaesu wind loading calculation
Hi All,
Looking at the Yaesu rotator manual for loading calculations it needs square meter area of the antenna to calculate if the rotator can handle it.

But, have a Jaybeam uhf long 24 ele yagi I'd like to use I checked the Jaybeam manuals and it gives only a kgf number.

Can anyone help?
I've looked up kgf which appears to just related to gravitational forces and not wind loading.

Mark

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Tue Jun 16, 2020 9:03 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
Is there not a similar antenna you can compare it against that gives metre squared.

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Tue Jun 16, 2020 9:48 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
Fair enough.
I compared it to a diamond 15 ele and doubled the wind loadings and all appears ok.

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Wed Jun 17, 2020 5:03 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
I'd be very surprised if any of the proper Yaesu rotators like a 450 800 1000 ect couldn't handle any single 70cms yagi with ease,

Different story if you have a 3el HF tribander and a 6m yagi and a 2m yagi, all at once then I'd be worried,

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Wed Jun 17, 2020 6:36 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
ei2glb wrote:
I'd be very surprised if any of the proper Yaesu rotators like a 450 800 1000 ect couldn't handle any single 70cms yagi with ease,

Different story if you have a 3el HF tribander and a 6m yagi and a 2m yagi, all at once then I'd be worried,

I had 4x9 el long yagis on 2metres turned by a yaesu 400 rotator for 22 years on a p60 never luffed it over in a storm, no issues at all until the feedback pot in the rotator went o/c, wouldnt be concerned with a 70cms yagi at all

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Wed Jun 17, 2020 8:29 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
As I will be using lower pole clamps the maximum ratings are halved. I believe this is due to the lower clamps not being not as strong as the rest of the rotator.
I will try to mount the yagi's clamp so it bottoms out on the rotator. Although the main boom is mounted on a lower boom which stops droop and adds about 2 feet to the height above the rotator.
It isnt the rotational power I am worried about but the tilting wind loading.
The calculations only allow for a maximum of 0.25 total loading from a wind loading multiplyed by height above rotator clamp in metres.
So my antenna at 0.3 x 0.6m = 0.18 , so will be ok.
If I extended the stub to 0.9m this would give 0.27 which is above the rating of the g450 rotator.

I suppose there may be a safety margin added by Yaesu so they cover themselves legally. Or is there? :)

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Fri Jun 19, 2020 11:10 am
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
picture below shows the Cushcraft A50-6s above an unsupported G400.

absolutely no issues.

Image

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Fri Jun 19, 2020 12:20 pm
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 Jaybeam to Yaesu wind loading calculation 
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Post Re: Jaybeam to Yaesu wind loading calculation
Thank you all,
Once assembled it is obvious it is going to be fine.
May add a few more antennas.

73

Mark

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Sun Jun 28, 2020 5:34 pm
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