Circular polarized antenna for 437 MHz

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This design produces the central part of a circular polarized antenna for 437 MHz (70 cm band), ideal for satellite and ISS communication. In contrast to the well-known turnstile design, this model makes use of the complex conjugate impedances of two V-antennas. Accordingly, it is key to get the elevation angles right, which this design ensures. The total impedance of this antenna directly matches 50 Ohm, so no further measures are necessary and the antenna can be connected to your HT or other UHF-transceiver right away. No need for delay- or impedance matching coax cables. This design is for a right-hand circular polarized signal (RHCP). As a result, this antenna only needs about an hour to be built, with most of the parts being available at the local hardware store for a few euros. In additon to the 3D-printed parts you will need: 1 m Aluminum rod, 6 mm outer and 4 mm inner diameter 4 screws M5x16, Allen key type 4 nuts M5 4 serrated washers M5 5 cm of thin 50 Ohm coaxial cable (e.g. RG316) 10 cm bare copper wire, 1.5 mm2 Ferrite toroids or bead, suitable for coaxial cable and frequency (e.g. FT23-43) BNC-connector, panel mount You will need to cut M5 threads into the aluminum rod, which is very easy to do but you need a tool for that.