Complex sentence: The longest distance over which reception of a long wave signal has been verified is, on 27 July 2015, when Mike Thayne received Radio NL on 358 kHz in England, transmitted from New Zealand.
Split into simpler sentences: The longest distance over which a long wave signal has been received is. It occurred on 27 July 2015, when Mike Thayne of England, received Radio NL on 358 kHz from New Zealand.