Just this past week I replaced the biggest UHF yagi that Radio Shack had, not sure of the number since I put it up years ago. In its place I put up a Channel Master 4248 UHF yagi which is physically almost the same size as the RS. The Channel Master out performs the Radio Shack on all stations in both strength and stability. The Radio Shack could bring in the stations but had a problem holding them. My area is troubled with mulipath reception (ghosting in analog TV). That can kill even a strong signal. The Radio Shack was also prone to loose the signal in bad weather.
The Channel Master was $47 plus shipping but more than worth the extra price.