VHF frequencies and digital television
One of the most common problems was the return to VHF frequencies by stations that had used them when they were analog. Over 480 stations were broadcasting digitally on the VHF spectrum after the transition, up from only 216 on the frequencies before. Many antennas marketed for digital TV are designed for UHF, which most digital stations use. VHF analog signals travel further than UHF signals, but watchable VHF digital signals appear to have a more limited range than UHF with the lower power they are assigned, and they don't penetrate buildings as well, especially in larger cities.
] Mike Doback, vice president of engineering for Scripps Television, said, "It's only now that we've found out the planning factors were probably wrong in terms of how much power you need to replicate analog service." According to TV consultant Peter Putman, the problem with VHF reception is that? VHF antennas must be large to be effective
, and indoor antennas do not perform well enough. In addition, channels 2 through 6 are more susceptible to many types of interference. Richard Mertz of Cavell, Mertz & Associates says multipath interference inside the house is also a factor. Some receivers can deal with this problem better than others, but there are no standards. And with amplified antennas or amplifiers, it is possible to overload a converter box. Amplifiers can also cause noise that is interpreted as data. Raycom Media Chief Technology Officer Dave Folsom said, "There's nothing inherently wrong with VHF. It's just easier to have interference, because it goes out further."