Formula for distance between 2 LNB.

[SENTHIL KUMAR]

In single dish , Sat hunting peoples install multi LNB setup for various satellites.

It is very difficult to fix the position of multi LNB in a dish.
But , there is a formula for multi LNB setting in a single dish.

For example,
6 FEET PRIME FOCUS DISH. ( you can apply this formula for any size dish ).

Diameter ( D) - 180 cm, Depth ( H ) - 30 cm.

step -1.

M = ( H / 2 ) + ( D*D / 8*H ) , M = ( 30 / 2 ) + ( 180*180 / 8*30 )

M = 150.

FOCUL LENGTH ( F ) = D*D / 16*H , F = 180*180 / 16*30

F = 67.5

Now calculate the value N.

N = M - F, 150 - 67.5 ,

N = 82.5


step - 2

for example : calculate LNB gap between Thaicom 5 and Measat 3a.

Thaicom 5 = 78.5 E, Measat 3a = 91.5 E.

Difference is 13 degree.

TAN Angle of 13 degree is ( T ) = 0.230

step -3

Gap between two LNB = N*T , 82.5 * 0.230 = 18.97 Cms.

So, LNB gap between Thaicom 5 and Measat 3a is = 18.97 centimeters.


( This gap is measure from centre to centre point of the LNBs )

 

[SENTHIL KUMAR]

You can apply this formula for any size of prime focus dish.

 

[amansingh]

You can apply this formula for any size of prime focus dish.

And for offset dish?

 

[SarfaRaZ]

Informative Share @Senthil Bro :tup

 

[Rahulan Raj]

Useful info Not for me though