Primary focus dish antenna feed support

thingiverse

Primary focus dish antenna feed support kit for M0EYT feeder with squeezed waveguide circular polarizer and Kumar ring choke. This is a three-piece kit, a central feed holder and strut hub, the strut holders that go in the edge of the dish and the optional waveguide holders to attach other items on a small aluminum board (pictures are self-explanatory). In addition to the feeder pieces by M0EYT, the board in my system holds the LNA, BP filter, PLL LO, Mixer and 10 MHz ref for the LO. The kit is designed for square section struts 10x10 mm and M3 Allen screws and nuts. You will have to calculate strut length taking into account your antenna dimensions (i.e., diameter and focus point location). The collar in the central feed holder is tapered in two sections to accommodate the back of the Kumar choke flush with the holder. The two perpendicular blocking screws go in the waveguide section of the collar. You can fine tune the focus location by a few millimeters (more or less depending on your dish f/D and hence choke location), if you miss the focus point recalculate strut length. You can also do longer struts with several adjusting holes in the side that goes in the edge of the dish. Printing directions Use PETG filament, please note that PLA is not suitable for these pieces. The material I use is by GEETECH, printing temp 240 C and 80 C on the build plate, ensure you have good layer adhesion (if not increase printing temp up to a max of 250 C). Printer here is Creality Ender-3 Pro. Layer Heigth 0.2 mm, Wall Thickness 1.8 mm, Top and Bottom thickness 1.0 mm. Infill density 40.0 Infill Pattern Cubic. Infill density below 40 and .8mm top/bottom thickness results in too much flex to my liking. You want a rigid system that minimizes differential flexure to ensure aiming accuracy.