2,401 Ghz source for the parabola
Helix antenna 6,5 turns left circular polarization

10X10 cm reflector
Helix diameter 40 mm
Wire diameter 6 mm
Spacing between turns 27 mm

Helix mount in teflon
Tunning plate 17 mm X 8 mm
 Helix/reflector spacing 15 mm


Other tunning system

I have built 2 helix anennas,
one in left circular polarizition
and the other in right polarization.
The tunning has been done by two
different ways.
A corner plate was placed close to the 1/4
of the first turn
The tunning is done by the spacing
of the corner plate with regards of the coil.
The corner plate is fasten to the ground.

Here is a solution to determine the focal point of the parabola wtih the
original 12 Ghz head mounted along the helix.
See below the used method