( ( Reception ( of ( ( radio waves ) ( with ( ( a ( frequency lower ) ) ( than ( 500 kHz ) ) ) ) ) ) ) ( ( is ( more ( complicated ( than ( shortwave reception ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Reception)) (PP (IN of) (NP (NP (NN radio) (NNS waves)) (PP (IN with) (NP (NP (DT a) (NN frequency) (JJR lower)) (PP (IN than) (NP (CD 500) (NN kHz)))))))) (VP (VBZ is) (ADJP (RBR more) (JJ complicated) (PP (IN than) (NP (JJ shortwave) (NN reception))))) (. .)))
Reception of radio waves with a frequency lower than 500 kHz is more complicated than shortwave reception.
(ROOT (S (NP (NNP Am) (NN radio) (NNS waves)) (VP (VBP exist) (PRT (RP in)) (NP (DT the) (ADJP (QP (CD 540) (TO to) (CD 1600))) (NN khz) (NN frequency) (NN range))) (. .)))