how about the wind stability of cheap (bigger)sat dishes?

[Turok]

Hello!
yesterday a friend from germany called me,and told me,that his lamias dish type 1800,with a size of 1,86m,was completly warped,after a heavy storm 3 weeks ago of around 90/km/h windspeed!
now the antenna,is ready to put in the tresh!

would be intresting to get some feed back,of windy areas,and diffrent todays dishbrands..


in all the antenna datasheets i find absolutly no information,about the hardness stability of the dishsurface?
what is the hardest dish ever made?,with the post affective wind stability ,would be intesting to find out?
most old manufactor,that out of bisness now,using in the past,like a wind simulation channel,with over 150 km/h wind test speed,to gurantee,that the dish can handle,this preasure,but how it looks,todays manufactors dont do this..!

 

[Channel Hopper]

Dish manufacturers (well good ones anyway) will usually have a high wind option to the standard reflector. It can either be made of thicker material, and/or have better supporting of the edges where the feed arms are installed.

Hardest material is probably the fibreglass/composite materials where not only is the ribbing part of the reflector, making for good resistance to warping, but the metal reflector is hidden away inside the composite.

Was your friend's dish a single piece or in partitions ?

 

[Turok]

Hi there!
the lamias dish,is a single non segment dish,but the material is very thin and flimsy like on the tordial dish also!
this explains the problem i would say!

how do you would calculate the contact surface,when the wind blows with 90 km/h to 1,80 m dish,how strong will be the force in (kg) of gravity then?

 

[BombedOne]

It all depends on dish and wind...

Some examples I've seen personally:

1. Dish turned INSIDE OUT.
2. Dish where metal was ripped off around bolts, so dish fly away.
3. Wind applied so much force on dish, that it ejected it's holder from the wall.

And don't say that this only happens to cheap dishes. Here's a picture, what a wind did to Professional, broadcast grade Prodelin dish...

 

[Channel Hopper]

And don't say that this only happens to cheap dishes. Here's a picture, what a wind did to Professional, broadcast grade Prodelin dish...

It's metal though.

Looks more like a Patriot dish to me..

 

[BombedOne]

Yes, it is Patriot, sorry for my error

 

[wod]

aren't those lamias dishes made of material like channel master as they looked fibre glass on the pics on their website.

tell your friend to get a 1.8 channel master as replacement that wont warp in windy weather

 

[Turok]

Hi!
i told him,before he purchase,but he dont want to belive me,but now he will do

i have for him a old hirschmann 1,86 m,that will do the job also!

the material is diffrent,but i dont know what kind of,the dealer says only it is reinforced plastic!

from polish mabo antennas,i heard,that the surface,will spoiled,after longer use,maybe around 8 years,and the kuband performance,will be then lower and lower,after many years!

some selfmade brands in czech republik when i look on some website are realy cheap,under 100€ for 1,80m,but i dont know,the brand,for cband use should be okay!

 

[BombedOne]

Here, Aserbaidjan made 180cm primefocus solid steel dishes perform quite well in Ku band, price is around $100. 150cm - around $60.

 

[Turok]

Hello!
do you have any datasheet of this dish?
intrsting would be to find out,is there a big diffrence in the gain winning,in the same price and size range,in other words,maybe we find also a cheap "good"dish when we search long time enough

todays mass consumer dishes mostly imported from turkey very cheap,and sold on ebay,by dealers,that bought a large number of them by high profit!
in macroco,like we read in the dishes on holiday topic,there are a lot of selfmade dishes!

all thris to make our selfmade dish,are still unsuxsessfull,because,we dont have the right material for,and die casting box is also mising!

 

[BombedOne]

No datasheets available...

Generally, they are much more alike Next & nextstar, supermax, gessat ones.

One point is, that seller advertises size of outer diameter, which is about 160cm. But effective, working diameter is only 148cm, so this dish should be considered as 150cm. Same for 180cm one - effective diameter is about 165cm.

 

[Telia]

Hello!
do you have any datasheet of this dish?
intrsting would be to find out,is there a big diffrence in the gain winning,in the same price and size range,in other words,maybe we find also a cheap "good"dish when we search long time enough

todays mass consumer dishes mostly imported from turkey very cheap,and sold on ebay,by dealers,that bought a large number of them by high profit!
in macroco,like we read in the dishes on holiday topic,there are a lot of selfmade dishes!

all thris to make our selfmade dish,are still unsuxsessfull,because,we dont have the right material for,and die casting box is also mising!

Ponny must have sold many Laminas in Germany?

 

[smiffie]

This might sound a dumb question, but if the site suffers from strong winds why not use a mesh dish? The stronger the dish, the more wind resistance it has and is more likely to act like a sail. I had a problem with a 95cm solid dish in the great storm of Christmas eve '97, but it wasn't the dish that failed, it acted like a sail and the H2H mount buckled.
It's in a very exposed location and I repaired the mount and welded a gusset on it for additional strength, then replaced the dish with an 85cm mesh. No problem since and reception hasn't suffered at all because I think the smaller dish has been built with more accuracy.

 

[Channel Hopper]

This might sound a dumb question, but if the site suffers from strong winds why not use a mesh dish? The stronger the dish, the more wind resistance it has and is more likely to act like a sail.

Because under even moderate winds, a mesh 1m for example will not perform as a good 1m dish should.

 

[Telia]

If you use microperforated mesh it will perform the same, if you keep the holes under 2.54cm which is the wavelength in KU-band it will be no problem.

Winegards old mesh dishes was a prime example of fine performing mesh dishes and then you have loads of mesh dishes designed for C-band which will not perform of course like the new mesh dishes from China being sold now.

 

[charly20]

Hello!
yesterday a friend from germany called me,and told me,that his lamias dish type 1800,with a size of 1,86m,was completly warped,after a heavy storm 3 weeks ago of around 90/km/h windspeed!
now the antenna,is ready to put in the tresh!

Hi Hans!

It does not surprise me.

I always thought that the Laminas were shitty. Too thin and too lightweight.

Experience confirms my belief about Laminas.

Charly20

 

[deepbluesky]

Hans, this is the 1st report about a warped Laminas that i read. It would be interesting to see how Ponny (the german importer) comments it.

Can you ask your friend from which direction the wind was blowing and where it was parked ? Obviously there was no place to install the dish save from strong wind gusts, right ?

 

[Channel Hopper]

If you use microperforated mesh it will perform the same, if you keep the holes under 2.54cm which is the wavelength in KU-band it will be no problem.

Winegards old mesh dishes was a prime example of fine performing mesh dishes and then you have loads of mesh dishes designed for C-band which will not perform of course like the new mesh dishes from China being sold now.

None of the above is true.

 

[zigmund]

Hello!
would be intresting to get some feed back, of windy areas, and diffrent todays dishbrands..

I'm in a high wind area, sorted the problem with a patio mount.
Everything now easy to get at.
Shielded by fencing on both sides.
Shorter co-ax feeder.
Could also be hidden by small evergreen bushes either side.
One big plus is that I have put a twin-walled sun shield covering the LNB.
Provides sun and water shielding, LNB even on the hottest of days rises only slightly above ambient. Before it used to get too hot to touch, and there used to be water in the co-ax problems.
Shield is two large thin walled plastic flower pots, with a spacer to provide twin-wall, mounted on a supporting post. LNB being offset is not directly in the beam, plastic is RF transparent anyway, so no loss of signal strength.
Yesterday had gusting to 70 mph. No problem, signal strength bargraph still full house.

 

[Turok]

Thank you ,for your input Zigmund!
and welcome,on board !
do you have a picture,of your setup?