Hawaii Puts AM Radio to Work on Maui.
Emergency officials in Hawaii will use AM broadcast equipment to help communicate with the public during the ongoing wildfire recovery efforts on Maui. The State of Hawaii Emergency Management Agency has purchased four RadioSTAT portable emergency advisory stations from Information Station Specialists in Michigan, which also makes specialized systems for applications such as Traveler’s Information Stations and Highway Advisory Radio.
The Wireline Competition Bureau of the Federal Communications Commission last week granted the state an emergency authorization to use the stations immediately at four locations including a checkpoint and police and fire stations. They can be used on 1620, 1650, 1670 or 1700 kHz.
The first of the four 10-watt ssystems has shipped, according to ISS. “These community-coverage radio stations are designed to inform residents and workers in Lahaina and at key checkpoints about where to find help and supplies and to update them on changing regulations that impact daily life, including curfews and safety requirements,” ISS wrote in an announcement.
Each station’s electronics are housed in portable cases. A fold-out antenna system allows a station to be set up in 10 minutes by one person. Messages typically are stored on a digital message player but the systems include an audio mixer for live messaging or to add other sources.
The signal is typically announced to the public by portable signage. Motorists typically can pick up broadcasts over 25 to 75 square miles. If AC power is not available the system scan operate from generator or battery pack.
Typical coverage radius over average soil is 3 to 5 miles with conventional whip-type AM antennas, according to Bill Baker of ISS. But for this application, he said the company is providing a taller, higher-efficiency antenna to counter the rather poor (volcanic) ground conductivity on Maui so the authorities can get the best range for the 10 watts. “When used in coastal placements — where most of the population is located — they will also get help from the shoreline salt water to conduit the signal parallel. In the middle of the island between the two end volcanoes is lots of relatively level farmland that may have higher conductivity due to the agricultural activities there.”
The FCC has an information page related to the Hawaii wildfires.
The full article in Radio World August 22nd, 2023.
Ron Trotto to WOR iog (2023-08-23)