I think that 9840's transmitter is located in So'n Tay(105.22E, 20.59N),Vietnam. 6175kHz's tx is in Sackville,Canada.
I can listen the program of 9840-VOV in Japanese with very good signal everyday. It seems that you can hear the VOV program at 6175kHz relayed via Canada.
1)Mr.Alan G.Davies' website,http://asiaradio.crosswinds.net/vtnlocs.htm
4)"Shortwave Guide to South East Asia",1999,Padula Books.
5)"Frequency list" replied from VOV.
Kyushu Is., Japan.