What are L and R polarisations ?

[Newb_Dxer]

Hi All,

We have usually heard about V and H polarisation but what are L and R polarisations like these ?
ChinaSat 9 at 92.2°E - LyngSat

Is a special Ku LNB be required for receiving these signals ?

Can any Techie friend help in understanding this ?

Thanks

 

[freedishlover]

L and R polarization is also known as circular polarization. Any normal LNB can be changed to circular polarization using special Teflon plate.

 

[Newb_Dxer]

L and R polarization is also known as circular polarization. Any normal LNB can be changed to circular polarization using special Teflon plate.

OK,
How to change the polarisation to circular on a Ku LNB ?
In C band we just insert a teflon or wooden piece in it whereas Ku LNB is closed.
Are you sure L and R polarisation means Circular polarisation in Ku signals ?

 

[shawl_who]

or a piece of tile as well :k

 

[Newb_Dxer]

or a piece of tile as well :k

Yes I have done that many years back at my village with Gardiner C band LNB and 8 feet dish.
But how to insert the teflon in a Ku LNB ?
Can any one show a ss ?

 

[Mr.Bhat]

L=Left Hand Circular Polarization, R=Righthand Circular Polarization...
inserting the Teflon Plate[or any other meterial to C Band LNB.. it should be placed cross to the sensor inside the LNB..
AFAIK there is no L,R in Ku band.. maybe in Foriegn Sats but didnt get ...
we can get signals without Using Plate too if the signal is strong... Put H to L and V to R...

 

[Mr.Bhat]

But how to insert the teflon in a Ku LNB ?
Can any one show a ss ?

I had done it for single Pol KU Band .. just open the white part of KU Band LNB... and put a smal peice across the sensor like in C Band... it was working then... now there is no need as LNB is Universal...

 

[ashoknaik184]

I am first time hearing from you that there is circular polarization in normal ku band transmission
The easy way to make a normal ku band lnb in circular you place a piece of circuit board of a old DVD or TV about 2mm thick 20mm long &broad as your inner diameter of your ku band feedhon & place it exactly between the two dipoles as shown in the SS.please remember to clean the copper side with sandpaper .it must be without any copper material.

 

[Newb_Dxer]

I am first time hearing from you that there is circular polarization in normal ku band transmission
The easy way to make a normal ku band lnb in circular you place a piece of circuit board of a old DVD or TV about 2mm thick 20mm long &broad as your inner diameter of your ku band feedhon & place it exactly between the two dipoles as shown in the SS.please remember to clean the copper side with sandpaper .it must be without any copper material.

Thanks for the info and ss.
I also came to know about Ku L and R polarisation from Lyngsat only.
If I am not wrong I think only Chinasats use Ku L and R polarisation ?
Does this mean that if we do not insert the teflon plate then there will be no signal at all even if beam reaches us ?

 

[ashoknaik184]

No it will only increase the signal from 15 to25 % for this type circular polarization there is no skew adjustment you can keep lnb at any degree