Here is a small introduction to the technical specifications that one may come across while building a parabolic satellite dish antenna.
The first thing that is common is f/D ratio which is the focal length f of the dish reflector divided by the diameter D of the dish.
Commercially available dish antennas have a f/D ratio of between 0.36 to 0.40 although 0.5 is also seen in imported antennas.
I prefer 0.38 for optimum signal reception.
Image 1 - The parameters of the satellite dish antenna indicated:
.
Image 2 - The dish antenna focussed properly with correct f/D ratio:
.
Image 3 - f/D ratio is high leading to bad reception:
.
Image 4 - f/D ratio is low leading to bad reception:
.
The first thing that is common is f/D ratio which is the focal length f of the dish reflector divided by the diameter D of the dish.
Commercially available dish antennas have a f/D ratio of between 0.36 to 0.40 although 0.5 is also seen in imported antennas.
I prefer 0.38 for optimum signal reception.
Image 1 - The parameters of the satellite dish antenna indicated:
.
Image 2 - The dish antenna focussed properly with correct f/D ratio:
.
Image 3 - f/D ratio is high leading to bad reception:
.
Image 4 - f/D ratio is low leading to bad reception:
.
