Isn't the radio fun? You can listen to it in the car, outside, or anywhere with plugs or batteries. You can hear the Sox game, or any random assortment of musical goodness. And supposedly, AM and FM attempt to de-randomify the assortment, but in recent years, as you probably have noticed, the line has become blurred. Back in the good ole days, shows were allotted AM or FM according to what they were, like music on FM and talk on AM, but as you have undoubtedly noticed, there is plenty of talk on FM, and all sorts of music on AM. And why does this matter, you may be asking yourself (for good reason!) What could possibly be the difference a weary reader might ask. Well, there is a difference! So, I ask: What is the difference between AM and FM? (Besides the channel numbers, that would be cheap!)
The difference is how their frequencies are altered. With AM, the strength of the signal is changed with the sound information. FM's frequency is varied, and is less susceptible to static. Since I did a terrible job at explainging that, for more info visit: http://www.pbs.org/wgbh/aso/tryit/radio/radiorelayer.html
Showing posts with label radio. Show all posts
Showing posts with label radio. Show all posts
Friday, May 29, 2009
Tuesday, April 21, 2009
April 21- Science
Radios are weird. They have all sorts of strange properties, like if you grab the antenna, the reception gets better. Another strange thing, that you may or may not have noticed, is that the reception is often times better at night. Which brings me to my question of the day: Why is the reception better at night? (Hint, it has to do with the sky)
In order to find a complete answer, we need to remember a couple of things. First, the earth is constantly revolving. Second, there are several layers of the atmosphere that keep said earth from frying. One such layer is the ionosphere. This is a layer of the atmosphere that has lots of ions very close to each other. Now lets look down at the picture. (Click on it to see the image in its entirety) You can't really see some of the writing I put on there, but, you can see the earth, and that white oval around it. Inside the oval is a purple line. That represents radio waves. Now, the left side of the earth is day, and the right is night. Since the ions are so close in the ionosphere, radio waves have to bounce off them. You can see that the ionosphere is closer during the day, so the radio waves have to bounce more, giving it more opportunity to get blurred. But at night, the ionosphere is farther away, so the waves can go farther in one bounce. This means you get a clearer reception.
In order to find a complete answer, we need to remember a couple of things. First, the earth is constantly revolving. Second, there are several layers of the atmosphere that keep said earth from frying. One such layer is the ionosphere. This is a layer of the atmosphere that has lots of ions very close to each other. Now lets look down at the picture. (Click on it to see the image in its entirety) You can't really see some of the writing I put on there, but, you can see the earth, and that white oval around it. Inside the oval is a purple line. That represents radio waves. Now, the left side of the earth is day, and the right is night. Since the ions are so close in the ionosphere, radio waves have to bounce off them. You can see that the ionosphere is closer during the day, so the radio waves have to bounce more, giving it more opportunity to get blurred. But at night, the ionosphere is farther away, so the waves can go farther in one bounce. This means you get a clearer reception.
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