When you complete the game, as in stopping the Reaper's Wrath, you can find it. You may be able to do this earlier on in the game. Here are the steps
1)you go to Gobi village (Asia).
2)Go to the exit that leads to the south Gobi plains, and there is a man by the exit, by the left pole.
3) Talk to him, and he complains about something to do with not strong enough opponents around here. Accept his quest.
4)Go to Kalimba Prak (Africa)
5) Exit by the south exit.
6) Head to the oasis, at the top towards the right of your map.
7)Walk around the lake, and a man should be there.
8)Talk to him. He give you an Alpha call drop +
9) Go back to the man in Gobi village. He complains about the man from Africa beating him
Now repeat these steps over and over again to get the Alpha call drop +
By JJ