Need a Lil bit o help please

So i just got my rode videomic i can definitely hear a difference in sound quality and it is definatley better but i seem to have a problem with static noise.. I have tried all the settings (exept changing the dB) but in the background of all my videos i seem to have a little bit of hi pitch noise.... idk what it is, it could be simple and if so try not to bust my balls too bad...