Grainy Pic quality on TV Capture?

If you've read some of my other posts, im trying to do some TV Capturing. With the TV Capture card im using, im getting really grainy image quality. The reception isnt bad because im getting some good IQ with the TV i was using at that outlet for some time (with same cable), but now with the capture card, im getting really bad IQ and wavy lines all over the picture. Im using mpeg2 at a bitrate of 40,000kb/s

Is it time to get a new TV Capture device? If so, what do you reccomend. Or if it's something else, could u tell me what it is?