This is a great feature for emergency situations or when you’re camping and don’t want to take extra batteries.Įxtendable antenna: Most AM radios have an antenna that extends from the radio for better signal reception. Hand crank: Some small AM radios have an additional option for generating power by using a hand crank. Power adapter: With larger AM radios, it’s helpful to have the option of running it from a power adapter plugged into an outlet. Larger radios may run from several C or D batteries, which cost more to replace. Small radios may use one or two AAA, AA, or 9-volt batteries. AM radios set themselves apart from each other through the extra features they offer.īatteries: Most AM radios run on alkaline batteries, although some use rechargeable batteries. AM radio featuresĪlthough all AM radios can pull in over-the-air radio signals in the 535 kHz to 1705 kHz band, these units can also do much more. The AM radio decodes the signal and turns it into an audio signal that plays through the speaker. The radio then ignores all other radio signals it receives. To pick up the AM radio signal you want, you dial the tuner to the proper frequency, such as 1620 kHz.
Others have a tiny antenna built into the radio body that you may never see or notice. Some have a silver-colored telescopic antenna that extends out of the unit. Reception: All AM radios have an antenna built in. And with the right atmospheric conditions at night, some AM radio signals can even travel 1,000 miles or more. This signal may travel a few dozen or a few hundred miles during the day, depending on the strength of the transmitter. This is where AM radios get their call numbers, like 590 or 1620. AM radio signals use frequencies between 535 kHz and 1705 kHz. Transmission: The station then uses an transmitter to broadcast the signal out to the world on a particular frequency. Modulation: The AM radio station encodes information (in the form of spoken audio or music) on a radio wave in a process called modulation. You may be surprised by how much has to happen before you can hear your favorite team’s baseball game on an AM radio. Radio station KDKA in Pittsburgh is credited with the first commercial AM radio broadcast, in October 1920.
0 kommentar(er)
