SENTHIL KUMAR
Banned
- Joined
- 13 May 2015
- Messages
- 302
- Reaction score
- 474
Focal length of the prime focus dish. ( c - band )
Focal length is one of the important number in prime focus dish.
This indicate which is the correct position to fit your LNB on scalar ring.
Calculation. ( Examble : 6 feet prime focus dish )
Diameter = 180 cm. ( D )
Depth = 30 cm ( d )
so, Focal length ( F ) = D*D / 16*d
F = 180*180 / 16*30 = 67.5 cm.
So LNB is fixed 67.5 cm distance from the centre of the dish.
Focal length of Offset dish ( KU BAND )
Focal length = ( w*w*w ) / ( 16*D*H )
W = width of dish ( 600 mm )
D = depth of dish ( 50 mm )
H = height of dish ( 700 mm )
Apply the values in formula.
Focal length = ( 600*600*600 ) / ( 16*50*700 ) = 385.7 mm.
we convert it into centimeter = 38.57 cm.
So focal length of offset dish - 38.57 cm
Focal length is one of the important number in prime focus dish.
This indicate which is the correct position to fit your LNB on scalar ring.
Calculation. ( Examble : 6 feet prime focus dish )
Diameter = 180 cm. ( D )
Depth = 30 cm ( d )
so, Focal length ( F ) = D*D / 16*d
F = 180*180 / 16*30 = 67.5 cm.
So LNB is fixed 67.5 cm distance from the centre of the dish.
Focal length of Offset dish ( KU BAND )
Focal length = ( w*w*w ) / ( 16*D*H )
W = width of dish ( 600 mm )
D = depth of dish ( 50 mm )
H = height of dish ( 700 mm )
Apply the values in formula.
Focal length = ( 600*600*600 ) / ( 16*50*700 ) = 385.7 mm.
we convert it into centimeter = 38.57 cm.
So focal length of offset dish - 38.57 cm