Our Basic Cable channels (2-50) are barely visible. What can we do and whats wrong?

We don't really have Shaw cable however we split our internet and sent one to the TV running through a VCR. We get a lot of the higher channels and even some HD ones however the lower ones you can barely see the picture and its all snowy and black and white. We do not have a HDTV but only a very old Toshiba CF19H22 (http://www.mercadolibre.com.ve/jm/img?s=MLV&f=15344527_7199.jpg&v=E) I would really appreciate any help with this since these are the channels we really want....