Dirgantara R - YFØEEE wrote:
hi
Any body know ?, in where i can buy Turnsytle antena for LEO Sat ? and cheap. I have some project testing Prototype LEO Sat.
73 de YF0EEE
Turnstile antennas are actually pretty easy to make. At its simplest, it's four bits of wire about 1/4 wavelength long, with a 1/4 wavelength phasing loop joining them. Note that the lengths of the elements and the phasing loop are going to be actually 1/4 wavelength multiplied by the velocity factor, which for the elements will be so near unity it's not worth bothering with (make them a tiny bit shorter *if* you need to), and for the phasing loop will be dependant on the cable used - 0.66 for RG58.
You haven't said which frequency range you want the antenna for, but on UHF I've had excellent results with the K5OE antenna, and I've also had a lot of success with the "cheap yagi" designs by WA5VJB. The latter I found a bit "narrow" to tune, though.
Gordon