My problems of Gnuradio

i want to build some simple project in gnu companion,such as cpfsk, fsk
,fmTaking cpfsk for example, i use three blocks: Random source , cpfsk
block , scope sink.The wave of scope sink is not correct i think.I hope
someone can send me some examples to my email and answer my questions. i
dont understand the meaning of samples/symbol.Thanks a lot