A simple ¾ wave vertical wire whip in the center of a car roof might make a good APRS Inmarsat
Downlink antenna. See: http://aprs.org/outnet-whip-ant.html
A ¾ wave monopole should have over 7 dBi gain above about 30 degrees which is where the Inmarsat satellite is. The patch antenna made by the Outernet Folks could be 9 dBi and also has the advantage of circular polarization but is critical to build unless one purchases their kit. But it would be useful to see if signals were possible from just the 6.0” whip?
And for people in the USA where the satellite is above 45 degrees, then maybe a 5/4 antenna might pickup another dB or so and still have the satellite in the main beam. Be nice to do an EZNEC model..
Bob, WB4aPR
*From:* Robert Bruninga [mailto:[email protected]] *Sent:* Wednesday, October 05, 2016 6:52 PM *To:* [email protected] *Cc:* Robert Bruninga *Subject:* Global Geo SATCOM system?
AMSAT tinkerers?
OUTERNET is a free worldwide Geostationary Satellite downlink system designed to bring content to remote areas all over the globe. They have six geostationary birds covering the entire globe EVERYWHERE. All you need is a small 18” (or 36” in some very remote areas) to receive content via your own home-made receiver based on a TV dongle and Rasberry Pi.
Is there anyone on AMSAT-bb that is already receiving this content? We’d like to hear about how easy it is to set up a receiver.
We have some ideas on how this can be used to augment Ham radio in our Emergency Response and remote operations missions. See http://aprs.org/outnet.html
Bob, WB4APR