Here is my construction of a right-hand circular polarized, omnidirectional Skew-Planar Wheel antenna designed for 1240MHz.
Designed for ground station use, the antenna was made after the following tutorial from IBCrazy:
0.75mm² copper wire was used for the antenna elements, some hot clue to fix everything and a piece of PVC tube to keep the antenna away from any metal parts of the tripod.
Due to fragility of the copper wire a Styrofoam ball will be used as a protection radom.
62mm is used as quarter wavelength.
Angle (green one) between the “eyes” on one S-shaped wire is 78-80°.
The angle (blue one) of quarter wave sections is 100°.
About fine tuning I found the following:
Green angle >90° will lower the resonance frequency while angles <90° will result in a higher resonance frequency.
Measuring results after proper tuning for 1240MHz:
Return Loss & VSWR