Complex sentence: The station was quite a mystery for a while, with thousands of ham radio operators and radio hobbyists speculating about the nature of the station, until a small news article in "Popular Electronics" magazine outlined exactly what WGU-20 was.
Split into simpler sentences: The station was quite a mystery for a while with thousands of ham radio operators and radio hobbyists speculating about the nature of the station. It wasn't until a small news article in "Popular Electronics" magazine outlined exactly what WGU-20 was.