( ( In ( April 1989 ) ) ( ( ( ( ( ( ( its ( 257 metres ) ) , ) ( ( ( 1170 kHz ) medium ) ( wave frequency ) ) ) ( was split ) ) and ) ( this ( became ( ( Great ( North Radio ) ) ( -LRB- ( GNR -RRB- ) ) ) ) ) ) . ) )
(ROOT (S (PP (IN In) (NP (NNP April) (CD 1989))) (S (NP (NP (PRP$ its) (JJ 257) (NNS metres)) (, ,) (NP (ADJP (QP (CD 1170) (CD kHz)) (NN medium)) (NN wave) (NN frequency))) (VP (VBD was) (VP (VBN split)))) (CC and) (S (NP (DT this)) (VP (VBD became) (NP (NP (NNP Great) (NNP North) (NNP Radio)) (PRN (-LRB- -LRB-) (NP (NNP GNR)) (-RRB- -RRB-))))) (. .)))
In April 1989 its 257 metres, 1170 kHz medium wave frequency was split and this became Great North Radio (GNR).
(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))) (. .)))