With cell phones, TVs and computers, who needs all those bands on your emergency radio? The answer sounds complicated but is pretty straightforward. Basically you need to stay connected during an emergency situation and when the power goes out and your cell is drained, an emergency radio is your lifeline to what is happening in the world.
For that radio to be really useful, it must have AM and NOAA bands. Let me explain.
AM Radio Bands – Still Necessary in an Emergency
Once upon a time, AM or amplitude modulation broadcasting was the only commercially important method for broadcast signal modulation, a signal, which contains speech and other sounds. It was the only way people heard news. For those who are interested, how it works is that an AM receiver detects radio wave amplitude variations at a particular frequency and then amplifies them. The most important thing is that the range of an AM station is determined by the power of the individual transmitter. At one time the US stations intended for wide-area communication during emergencies operated at up to 500,000 watts. Then, The Emergency Alert System (EAS), the national warning system put into place on January 1, 1997, superseded these "super-stations." In plain language, EAS takes over the frequency control of AM stations all over the United States to allow the broadcast of emergency messages simultaneously. It is tested regularly at different levels in weekly, monthly and annual tests. We've all heard those "we interrupt the regular programming …" test moments on the radio.
FM Radio Bands – Good but Usefulness Can Be Uneven
FM broadcasting is a technology that provides high quality (fidelity) sound. While AM ??radio transmitters bounce their signals off the atmosphere and sometimes can be heard thousands of miles away, FM transmitters are essentially line-of-sight, unless there is a relay system set up. During a national emergency, FM stations will transmit the same emergency as AM stations, but their reach is not as broad and reception can be spotty.
NOAA – Broadcasts Continual Weather Information
The National Oceanographic and Atmospheric Administration (NOAA) sponsors NOAA Weather Radio All Hazards (NWR). This is a nationwide network of radio stations broadcasting continuous weather information directly from the nearest national weather service office. NWR broadcasts official Weather Service warnings, watches, forecasts and other hazard information 24 hours a day, 7 days a week. The "other hazards" include all types – natural disasters such as earthquakes or avalanches, environmental hazards, such as chemical releases or oil spills, and public safety problems, such as AMBER alerts or 911 Telephone outages. It operates on radio bands ranging from 162.400 to 162.550, and therefore is not available on a standard AM / FM Radio.
It is provided as a public service by the Department of Commerce. NWR covers all 50 states, adjacent coastal waters, Puerto Rico, the US Virgin Islands, and the US Pacific Territories with over 1000 transmitters ,.
This is why your emergency radio should be able to receive AM and NOAA signals.
Source by Abby Kendall