Complex sentence: In 1981, KARV made the move from 1490 AM to a much more powerful frequency of 610 AM, which with the low spot on the dial, covered much of the state of Arkansas.
Split into simpler sentences: In 1981, KARV made the move from 1490 AM to the more powerful frequency of 610 AM. With its low spot on the dial, KARV 610 covers a large chunk of the state of Arkansas.