17 Jul
2013
17 Jul
'13
3:32 a.m.
On 2013.07.17 10:11, Simone wrote:
Hi Phil,
QFH is effectively circularly polarized, it is often used for GPS receivers, since when you point it skywards the main lobe points trough the zenith, while nulls are pointing to the horizon (where you do not have satellites normally).
In my opinion QFH risks to be quite bulky for a balloon, since it will occupy a cylinder 1 wavelength high (70cm in your case).
QFH for 70cm band is 264 mm height only (and 84 mm in diameter).
73!