need help

[jagm]

I found a person who has a 6 foot dish, it is not solid and has nothing but the dish. if I get it, would the arm and LNBF work there?, should it be in the same position as the actual (a) or shoul it go at the center of the dish (b)?

 

[Mr Tony]

if its a prime focus dish it goes in the middle

 

[jagm]

what should be the distance from the dish?, can I use the same arm?