When a Dongle is purchased, a whip antenna is supplied with it. Every beginner uses this whip in his starter setup.
Improve the performance of this whip antenna by three simple steps given below:
(1) Whip is too long for 1090 MHz. Cut it to 67mm.
(2) Magnetic base provides an insufficient ground-plane. Enlarge ground-plane by placing the whip over a Metallic Can/Box/Plate. An added advantage of placing whip over an iron/steel can is that whip's magnetic base will cling to the can and keep the whip stable & upright.
(3) Signal is weak indoors. Place whip near a window or in attic to get maximum signal.
(http://tjharris.id.au/radio/antenna.png)
Hope this helps someone !!
James
If anyone's interested, this is the original, unedited post from the FlightAware forum, published last November.
http://discussions.flightaware.com/post184234.html#p184234