Let me introduce an example of reception of overseas MW station in Japan.
This is a reception record of Australia 4QN on 630kHz at 10:00 UTC on May 2 in 2016.
The radio station 4QN is transmitted from Brandon Queensland in Australia that is about 6000 km apart from the reception point. 4QN is one of very popular overseas MW stations caught in Japan.
Google map: Australia 4QN, Brandon QLD
We set up a twisted double delta flag antenna beaming to south east at a cliff facing to the Pacific Ocean in Chiba prefecture. The received signal was so strong and the program could be heard very well like Japanese local radio. Sea gain effect also helped to catch such a nice signal too. The another weak English program also can be heard on the same frequency. This is KUAM from Guam island.