SatNOGs No-Rotator Setup
Thank you to Silvia P. for writing in and letting up know about the SatNOGs “No-Rotator” project, which looks a lot easier to build compared to their motorized rotator. SatNOGs is an idea and organisation that is trying to make it easier to set up a low cost networked RF ground stations for monitoring various satellites. The idea is to increase satellite ground station coverage all over the world and collect and share received satellite data over the internet so that anyone in the world can view and make use of up to date satellite data.
An original SatNOGs station is built as a motorized antenna rotator, with directional antennas that point and track satellites as they pass over the ground station location. The gears and most internal plastic parts are 3D printed, with the rest of the items like bearings, frames and motors being available on eBay. The problem is that building the rotator is quite a big project, and takes a lot of research, purchasing and building to get started.
Recently over on their Wiki a new type of non-rotator ground station has appeared. The no-rotator ground station still consists of the basic SatNOGs electronics including an RTL-SDR and Raspberry Pi. But instead of using high gain directional motorized antennas this ground station uses a much simpler turnstile antenna tuned to about 137 MHz. Unlike the rotator, the turnstile probably doesn’t have enough gain to pick up some of the weaker amateur satellites, but should be good enough for NOAA/Meteor weather satellites and ISS APRS etc.
We’ve also recently seen similar no-rotator builds discussed over on their forums and on Twitter.
So I go to the SatNOGs Wiki page linked in the post and what do I see? NOTHING really except a lonely picture of a turnstile antenna. And that’s IT regarding the antenna. Typical SatNOGs B.S.
http://wiki.satnogs.org/No_rotator
Discoverability could be improved, but do your homework 😉
So SATNOGS just discovered the Turnstile antenna? tell them about the QFH then!
Sorry but reading this looks like there is some new project involved but i know that the turnstile antenna was used since the beginning from many of them.
In any case good link, they deserve more attention.
Double Turnstile antenna ?
http://www.g8seq.com/vhf_antennas.php
Generally they are just called Turnstile, with or without reflectors. The classic version has passive reflectors; in the one linked both sets of dipoles are connected in parallel.