The South Korean Defense Ministry reportedly (North Korea Tech) stepped up shortwave radio broadcasts into North Korea from 9 August.
Why?
The North jams most, if not all, of the signals, few North Koreans own shortwave radios, and decades of similar expense and effort have resulted in … well, nothing.
Instead of spending money on radio programs no one can listen to, using signals the North will jam, it’s time for a new tool. The South should be investing in cellphone towers along the DMZ and in supporting efforts by defectors to infiltrate phones into the North (read more on those efforts from The Asahi Shimbun or The Atlantic).