Parabolic Dish with BiQuad feeder - Page 2
Saturday, 12 September 2009 22:20

biquad with 30mm lipsReflector

Cut a square piece of blank printed circuit board, 110 x 110mm.

Note: To further increase performance attach 30mm high lips to two sides of the reflector, to reduce side radiation. (image on right shows a completed biquad with 'lips').

Use some steel wool to remove any tarnish and polish it up. Cleaning the copper in this way will make it easier to solder.

biquad pipe notchCut a 50mm section of copper pipe, and file both ends smooth using sandpaper and/or metal files. Polish up the copper pipe (including the inside of the copper pipe), to ensure a good connection with the coax braid.
short secion of copper pipe, notched at one endCut a notch into one end of the copper pipe, removing approx 2mm from half the circumference.
making a hole in the centreDrill a hole in the centre of the blank PCB so that the copper pipe fits tight in the hole. I found a reamer to be very useful for enlarging the hole to the correct size.
insert the copper pipe into the reflectorInsert the copper pipe into the hole, with the notched end on the copper side of the blank PCB. The copper pipe should be protruding approx 16mm through the hole, measured on the copper side of the PCB.

 solder the copper pipe to the PCBSolder the copper pipe to the PCB, to ensure a good physical and electrical connection.