KG-ACARS http://sky.geocities.jp/kgacars/indexworld.html
Popular ACARS frequencies in MHz:
131.550 Primary Channel worldwide
129.125 / 130.025 / 130.425 / 130.450 / 131.125 / 131.475 / 136.700 / 136.750 / 136.800 / 136.850 for USA & Canada
131.250 / 131.450 / 131.950 for Japan
131.450 for China
131.525 / 131.725 / 131.850 / 136.750 / 136.900 for Europe