Simple UHF antenna for HDTV
 

This crude yagi made a big difference in HDTV reception in an otherwise noisy apartment (a fair amount of impulse noise). The driven element consists of RG59 coax center conductor for half the element, and the other half is the outside shield. Ferrite beads separate (with respect to RF) the outside shield's outside from the rest of the coax that runs to the converter box. The shield's inside and center conductor doesn't "see" the beads. See diagram. And it's all taped to a sheet of cardboard.