Why can’t I receive NBC’s DTV signal?
I cannot receive your DTV signal. I can receive your analog signal but when I hook up my converter box I can’t receive your digital signal. I can get channel 6 and channel 10 which are from Columbus but can’t get channel 4. I will miss your news and weather when Feb. 17 comes. Is there anything I can do to get your digital signal?
We spoke to Deb Grivois, WCMH Director of Engineering and Operations, she says it sounds like you are experiencing what’s called cliff effect. When a digital signal gets weak enough, you don’t receive the signal. You may have to investigate whether a different antenna can improve your reception. If your antenna has a variable amplifier, you might try increasing the amount to see if that helps.
TV reception can be weakened by many factors like terrain, trees, buildings, weather (rain, wind, humidity), and damaged/deteriorated equipment. According to a recent study for the digital television transition, many viewers watch analog signals that are less than ideal, perhaps with a little bit of noise or some chrominance loss. However, digital signals exhibit a cliff effect so that unless signals are well above levels that many people consider acceptable for analog, the digital signal will not work at all. The cliff effect happens when the digital signal falls below a certain minimum strength. The picture will suddenly disappear.
Digital transmission is line of sight from the transmitting antenna to the receiving antenna. The digital signal is straight and doesn’t follow the curvature of the earth. Most of the digital channels today are on UHF frequencies. UHF signals don’t travel as far as VHF signals do. Although we’ve had viewers who live as far as 70 miles away tell us they have a good signal strength, others in hilly areas like yourself haven’t had the best of luck. Beyond 60 miles, digital reception is trickier.
Because of all of these factors, we’re suggesting viewers inspect their antennas. Some may require an adjustment to the elements; some may need re-orientation; some may need a height change, and some may have to be replaced with one that has higher gain. We have been suggesting this website to get answers to reception questions, http://www.antennaweb.org. It has quite a bit of information on the transition to digital television. I’ve seen a lot of articles recently about antenna orientation and the need to upgrade antennas because of the change to digital television.