This week-end (september 3rd and 4th) will take place the All Asian DX Contest. You could expect stations from all over Asia and Oceania to enjoy the contest. Vietnam will not be outside the competition and at least XV4Y will be active during the evenings (1300z-1600z).
Next week-end will see participants from all over the world run in the AA DX Contest organized by JARL. You can expect stations from Vietnam to be active like last years.
As always, XV1X should be the major station. Also listen to XV4Y on 10m and 80m as he may have some spare time for a few QSOs.