SENTHIL KUMAR
Banned
- Joined
- 13 May 2015
- Messages
- 302
- Reaction score
- 474
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 )
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 )