Complex sentence: CH's large antennas could be seen from the French coast and meant the Germans were aware of their precise location, and their fixed direction broadcasts towards the continent meant it was easy to determine which signal was broadcast by which station.
Split into simpler sentences: CH's large antennas could be seen from the French coast and meant the Germans were aware of their precise location. Their fixed-direction broadcasts towards the continent meant it was easy to determine which signal was broadcast by which station.