Hi, I checked on Dual-axis Antenna Systems most of them have Azimuth Travel: 120°. why not 180° ?
http://www.servsat.com/_pdfs/1 VIKING Antennas-3.0m 3.4m 3.7m C and Ku Band.pdf
http://www.servsat.com/_pdfs/1 VIKING Antennas-3.0m 3.4m 3.7m C and Ku Band.pdf