I came across this antenna design by HugeOne at FPVLAB. I found the antenna to be rather complicated to build as specified in the tutorial, so I made some modifications to the process that seem to ease the build and produce results with much higher tolerances. This tutorial shows how to build a 5.8GHz turbine RX antenna, at the end of the tutorial I have listed the measurements necessary to build a 3-blade TX fan antenna.
Parts & Tools
SMA Pigtail Cable or RP-SMA Pigtail Cable*
* (Standard SMA compatible with Fatshark, RP-SMA compatible with this)
Solder & Flux
Needle Nose Pliers
Begin by cutting eight wires to a length of precisely 1.751″. This is best accomplished by using wire cutters to make a rough cut at about 1 13/16″ and then filing the wire to the proper length.
Bend the wire 90 degrees after the 0.660″ mark. The resulting segment should measure about 0.680″ from the outside of the bend.
Bend the wire 120 degrees inward after the 0.303″ mark. The resulting segment should measure about 0.323″ from the outside of the bend.
Bend the wire 120 degrees inward after the 0.698″ mark. The resulting segment should measure about 0.718″ from the outside of each bend.
The lower segment should be bent slightly outward with close attention paid to the proper polarity. Each blade should be angled 45 degrees away from the small center wire.
Use a template, such as the one depicted below, to properly align the blades 45 degrees apart. Use double sided foam tape or another temporary adhesive to hold the blades in place. A piece of scrap below the top wires will help to prevent the solder from melting to the lower wires.
Carefully remove the antenna from the template.
Strip the coax cable and tin the shielding of the cable. cut the tip of the cable to expose the core.
Solder the lower wires to the outer shielding prior to soldering the core to the center of the top wires.
Wire Length = 1.796″
Mark One = 0.561″
– Segment One = 0.581″
Mark Two = 0.454″
– Segment Two = 0.474″
Mark Three = 0.671″
– Segment Three = 0.711″