...then tweak your setup

UHF signals are sensitive to interference, and trees and buildings can obstruct signals, so don't expect to get all digital channels on the first try.

If a specific station doesn't come in, reorient the antenna and run another channel scan, or enter the channel number (if the box allows that). Adjust the antenna in various directions or move it closer to a window, which might require a long cable. Use the signal-strength meter (many DTV boxes have one) to adjust the antenna to the optimal position. You might have to tweak the antenna each time you tune in a station with marginal signal strength.

Still no luck? Try an amplified antenna or a signal booster. Last resort: a rooftop antenna. In our tests, we use a standard residential rooftop antenna we've had for years, not a special "digital" or "HD" model. In general, AntennaWeb.org notes, bigger is better, higher is better, and closer (facing the transmitter) is better. The site recommends the type of antenna you'll need, based on distance from the transmitter and details you provide on obstructions and dwelling type.