FM broadcasting
VHF Radio waves do not travel far beyond the visual horizon, so reception distances for FM stations are usually limited to 30–40 miles (50–65 km) They can also be blocked by hills or buildings.
Campus radio
Most of the FM radio stations received higher-class licenses than ten watts, typically a few hundred watts. A few got several kilowatts, and a small handful got licenses in the range of tens of thousands, sometimes reaching up to maximum-power 100-kilowatt outlets. WRAS 88.5 FM and WREK 91.1 FM in Atlanta are the most powerful college radio station, operating at 100,000 watts. Still, due to strict class D regulations, some radio stations were prohibited from a wattage upgrade for possible signal interference with adjacent radio stations, such as KWUR 90.3 FM interfering with KWMU 90.7 FM in St. Louis, Missouri. KTUH 90.3 FM in Honolulu, Hawaii has had many increases in its wattage since they started broadcasting at 10 watts as a Non-commercial educational FM radio station in 1969. In 1984 KTUH received permission from the Board of Regents to increase to 100 watts of power. More recently, in 2001, KTUH began transmitting at 3000 watts of power. KTUH is heard on an island wide frequency in Honolulu, Hawaii from 90.1 FM, as well as online at KTUH.ORG and on digital cable channel 866.