I have seen some construction details on this forum of an omni-directional ariel with diamond shaped segments which has more gain than a a spider/cantenna.
Does anyone know what its called so i can search/google it?
1 Like
May be “omni-quad”.
Most common is “bi-quad”, which is directional.
Never tried any type of quad. Dont know if these are high gain or not.
Here is one “omni-quad”
Omnidirectional Biquad Antenna for 2 4GHz - YouTube)
The signal from airplanes are vertically polarized. Some antenna that are circular polarized might not work that well for vertical polarized signals.
Dipole pole and loop antenna are very good with vertical polarized signals.
Maybe you can find the one you saw on this page?
antennamagus.com/antennas.php?page=antennas
Quadcopter are using circular polarized “clover leaf” antennas. These are much better than most antennas but require both the transmitting and receiving antennas to be the same.
I don’t know how good a circular polarized “clover leaf” antenna will pick up the ADSB signal.
Thanks folks, biquad was the magic word and that youtube shows it being made, 2 biquads at 90 degrees. will give it a try and see how it compares. Thank again.