Regardless of what LNB you're using (as long as it is a Star Choice/Shaw Direct LNB), you need to be in the "right" menu and on the "right" channel on the receiver or else it's not actually providing a real signal reading.
I say this because once it is, with a SD receiver you can get picture with a signal of around 30. (However would still want to max it out after this).
If you have a really old receiver with the full-screen grey menus, make sure you're getting the signal from OPTIONS 6-3-1. Before this, tune to channel 299 (if you can't get to 299, make sure you go to 284).
If you have a mid-generation receiver with the picture-in-guide window (pictured below), get the signal from OPTIONS 6-4-3-1. Before this, tune to channel 299.
This will tell you what the signal actually is and should help narrow down whether you're on the right track or not. I'm guessing you're using a round dish (not the elliptical football-shaped one). What does the LNB look like? Is it a cylinder or more of an L-shaped thing? Are there one or two ports?