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Is There A Radio That Can Pick Up AM/FM Stations Nationwide?


citykid09

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Is there a radio that can pick up am/fm stations nationwide?

Is this possible?

I want to listen to this radio station in Los Angeles all the way here in Bryan/College Station. Is there a radio that can get stations from anywhere I want?

If not I wonder if it would be possible to make one.

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I saw a radio the other day in a store that said it could get stations Worldwide! But I think there is a catch to that. So if that can do it worldwide, why not nationwide?

You probably were looking at a shortwave radio. They can pick up stations worldwide, but they broadcast on a different frequency range than FM or AM radio. Your best bet for the LA station is the internet.

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Is there a radio that can pick up am/fm stations nationwide?

Is this possible?

I had picked up FM stations from 45 of the 48 lower states from my home in Wisconsin. This takes a lot of time, good hardware, and excellent location, sometimes a big tower, often a giant antenna array, modification of the front end and IF sections of your FM radio, good coax, and you still might only pick up 1 station (not of your choice) out of 200 from a state for only 5 minutes in an entire year.

Generally FM stations are limited by the height of the transmitting and receiving locations because it is mostly line of sight around the curvature of the earth. A general rule of thumb for FM stations is they'll reach twice as many miles as the square root of the tower height in feet. Houston has some of the tallest towers in the nation, which are ~2000 feet. (2000^.5) * 2 = 89 miles. LA has taller stations because they put their towers on Mount Wilson, but they'll never reach anywhere near this far. Even if they were on a mountain taller than Mt. Everest, there are many more local stations on that same frequency that'd probably swamp out the signal.

The reason why FM stations are generally only line of sight, is because they go right through the atmosphere into outer space. AM stations at night are different though, as they bounce off the atmosphere and can reliably make it say 1,000+ miles depending on local conditions. In Dallas I can listen to a Chicago 50kw AM station at night for instance. The difference is the frequency range. FM stations are around 100Mhz and AM stations are around 1MHz.

FM stations bounce like this every once in a while, usually during the summer and its called ducting. You may notice your local Houston stations may be interfered with every few weeks during the summer in the mornings by stations from hundreds of miles away, and this is usually ducting. You can't control where the stations come from or how long it lasts though.

So if its an FM station you're out of luck for over the air reception. They have Internet appliances that allow you to broadcast a TV or FM station from your personal computer, and if you had a friend in LA you could have him plug one of these into an unused stereo. This assumes the station isn't already on the net.

The "world" radios you're talking about are referring to lower frequencies like AM is so you can get some stations from around the globe.

Jason

Edited by JasonDFW
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Many AM and FM stations used to have their programs on the internet. Then a couple of years ago the people who do voices in commercials sued in court and won because they weren't getting extra money from the stations that were on the internet. So, many stations reacted by pulling their streaming audio altogether.

Since then, a number of stations have figured out ways to automatically replace their local commericals on the internet streams with either music beds or custom commericals just for the internet audience. But there are still far fewer radio stations streaming on the net than there used to be before the lawsuit.

As for picking up AM stations over the air, this is possible in some areas -- mostly the northeast and midwest where "clear channel" (the concept, not the company) AM stations operate at maximum power without interference from other stations. For example, in Minneapolis over the holiday I was able to listen to WGN/Chicago, WSM/Nashville, WSB/Atlanta, and WCBS/New York. When I moved to Houston I was very disappointed that no clear channel AM stations penetrate that part of Texas. Even WBAP/Dallas, which is also a clear channel station, didn't reach me in downtown Houston for some reason. However, while driving west on I-10, I was able to listen to a Los Angeles radio station from San Antonio to El Paso (as far as I went) because it, too, was a clear channel station.

As for FM signals -- no, it just won't work. America is too big for an FM signal to cover. It would require too much power and give people living within 100 miles of the tower complex radiation burns.

Which brings us to short wave -- You can receive radio stations from around the world on shortwave, even in Houston. But there are fewer and fewer of these stations operating these days because so many people get their information from the internet. The BBC recently stopped transmitting its programs to North America because so many people listen to BBC on their local public radio station or the internet or satellite services like Sirius.

What you get from shortwave radio listening are international radio stations, not necessarily American ones. There are maybe 20 shortwave stations in America, and only about four or five that can be received reliably. There used to be more, but during World War II the government shut them all down. The reasons are varied, and beyond the scope of his writing. It should be noted, however, that many prominant AM stations were also shut down at times during the war because Axis planes were able to use their transmissions as homing signals. Today it is illegal to operate a commerical shortwave station in the United States. Stations like WWCR/Nashville, or WHRI/Noblesville are allowed because of two things -- 1. they're primarily religious in nature and non-profits. And 2: their signals are beamed out of the country. Because of the nature of radio waves you can pick up their signals here in the United States, but that's just spillage, not primary coverage.

And let's not forget satellite. If you have a TVRO dish, you can listen to some radio stations which are carried on the subcarriers of various Superstations. For example, WPIX/New York has WQCD-FM on its subcarrier. WGN/Chicago has WFMT-FM on its subcarrier. But if you're the kind of person who only has Sirius or XM radio, then you're not going to get a local station. XM and Sirius are prohibited by law from carrying local stations. In fact, they're prohibited from carrying local content, and the local broadcasters are in a tizzy about the traffic reports on Sirius and XM. At one time XM had a station it called KISS-FM, and modeled it after KIIS/Los Angeles. A lot of people thought it was the LA station, but it wasn't. Sirius carries something that sounds very much like WSM/Nashville, but it isn't. It's very close, but it's not the real thing in order to avoid running afoul of the FCC.

Any other questions? I'm just full of answers tonight.

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As for FM signals -- no, it just won't work. America is too big for an FM signal to cover. It would require too much power and give people living within 100 miles of the tower complex radiation burns.

It's not the power that limits those FM station's coverage, it is the antenna height. The 320,000 watt WBCT is plenty strong to cover the US (assuming no co-channel or adjacent channel interference), but its antenna is too low. Just as a point of reference, I've picked up 4,000 watt stations from the Sears Tower 250+ miles away full quieting.

As for radiation burns, a cell phone at your ear gives you a stronger signal than a 5,000,000 watt UHF station at the strongest point (generally a couple miles away) from the tower.

jason

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Like travelguy said, I think the only way that you can go nationwide is with an XM or on some sort of Internet Radio, but those aren't always the best.

I've been having my XM Satellite Radio for a year and a half. It's pretty good. You just have to make sure that you have the antenna pointing to the south.

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It's not the power that limits those FM station's coverage, it is the antenna height. The 320,000 watt WBCT is plenty strong to cover the US (assuming no co-channel or adjacent channel interference), but its antenna is too low. Just as a point of reference, I've picked up 4,000 watt stations from the Sears Tower 250+ miles away full quieting.

As for radiation burns, a cell phone at your ear gives you a stronger signal than a 5,000,000 watt UHF station at the strongest point (generally a couple miles away) from the tower.

jason

You are correct about height being a very important factor in how far FM singals travel. In fact, it's probably the most important factor. In my mind when I was writing my previous post I was thinking about a theoretical tower of unlimited height.

As for WBCT/Grand Rapids, it does not put out 320,000 watts. That's ERP -- effective radiated power, meaning it puts out a much small number of watts from the top of a tall tower (in this case, 1,130 feet above the ground). For example, WHTZ/Newark's transmitter pumps out 3,000 watts, but bills itself as a 50,000 watt station because that's the ERP you get from being on top of the Empire State Building. You can also further fudge the numbers by using a directional antenna or beam tilt. However, in the case of WBCT, neither of these apply.

As for RF burns, you can get them off some pretty low-powered equipment if you're close enough for long enough. There area a lot of good-old-boy engineers who will climb a tower and fix a problem without turning the station off if the owner slips him an extra hundred bucks or so. I know two (one now deceased) who have extensive swirling burn patterns on their arms from doing this on stations putting out as little as 1,000 watts AM and 3,000 watts FM.

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I used to get KOA quite clearly when I lived in Wisconsin, and occasionally when I lived in Ohio.

My dad is a retired airplane pilot. He told me that years ago he flew by the antenna in south Louisiana of 50,000 watt AM radio station WWL in New Orleans. He said that it was 2,000 (that's right, TWO THOUSAND) feet high. An awesome sight!

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There was a day a few years ago when the atmosphere was really odd. I was not living in Houston at the time, but noticed that morning in the car that I could not get any of my usual stations from Houston, Beaumont, and Lufkin to come in at all. I hit the scan button on the radio and it stopped on a station that sounded pretty good, and had a good clear signal. But it was on a frequency that normally nothing came in on. After a few minutes I realized I was getting a morning show from a FM station in the Washington, DC area! It was loud and clear, so I kept it on that station for the rest of the day. By about 2:00 PM it was no longer coming in at all - just static on that frequency, and the "local" stations were coming in again. It was really strange, but kind of cool to listen to DC radio while driving around Southeast Texas.

Now that I have a car with XM, I hardly listen to Houston radio at all while driving. I've thought about XM for my home stereo, but don't know that it's really worth the cost since I'm not home to enjoy it that much. And the digital music stations on cable are almost as good for nonstop, commercial-free music.

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My dad is a retired airplane pilot. He told me that years ago he flew by the antenna in south Louisiana of 50,000 watt AM radio station WWL in New Orleans. He said that it was 2,000 (that's right, TWO THOUSAND) feet high. An awesome sight!

Height matters a lot for FM stations. It matters very little for AM stations. The height of an AM tower is dictated by the frequency the station is on. The lower the frequency, the taller the tower. Since FM stations are all on comparatively high frequencies, their antennae are actually pretty small. You could easily fit one in the trunk of a car. So, FM antennae have to be mounted on tall towers, frequently tall AM towers where the entire tower is the AM anteanna.

Another example of the lower frequency=longer/higher antenna can be seen in the woods of northern Wisconsin where the Navy has a transmitter for a very low frequency transmitter used to communicate with submarines around the world. The frequency is so low that the antenna is strung along telephone poles for miles and miles.

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There was a day a few years ago when the atmosphere was really odd. I was not living in Houston at the time, but noticed that morning in the car that I could not get any of my usual stations from Houston, Beaumont, and Lufkin to come in at all. I hit the scan button on the radio and it stopped on a station that sounded pretty good, and had a good clear signal. But it was on a frequency that normally nothing came in on. After a few minutes I realized I was getting a morning show from a FM station in the Washington, DC area! It was loud and clear, so I kept it on that station for the rest of the day. By about 2:00 PM it was no longer coming in at all - just static on that frequency, and the "local" stations were coming in again. It was really strange, but kind of cool to listen to DC radio while driving around Southeast Texas.

Now that I have a car with XM, I hardly listen to Houston radio at all while driving. I've thought about XM for my home stereo, but don't know that it's really worth the cost since I'm not home to enjoy it that much. And the digital music stations on cable are almost as good for nonstop, commercial-free music.

I've had my XM home unit since May of 2004. I like "surfing" it.

Height matters a lot for FM stations. It matters very little for AM stations. The height of an AM tower is dictated by the frequency the station is on. The lower the frequency, the taller the tower. Since FM stations are all on comparatively high frequencies, their antennae are actually pretty small. You could easily fit one in the trunk of a car. So, FM antennae have to be mounted on tall towers, frequently tall AM towers where the entire tower is the AM anteanna.

Another example of the lower frequency=longer/higher antenna can be seen in the woods of northern Wisconsin where the Navy has a transmitter for a very low frequency transmitter used to communicate with submarines around the world. The frequency is so low that the antenna is strung along telephone poles for miles and miles.

I remember one time when I bought a new car radio, the manual said that your AM will lose reception when you drive under an overpass or through a tunnel, but that your FM won't. It was true. I wonder why?

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I remember one time when I bought a new car radio, the manual said that your AM will lose reception when you drive under an overpass or through a tunnel, but that your FM won't. It was true. I wonder why?

It depends on the length of the tunnel. In a short tunnel you may not lose either. In a medium sized tunnel you'll lose AM because the waves can't penetrate below ground, though they do run along the ground (groundwave). FM signals will travel farther into the tunnel because of their higher frequency they will bounce off the walls.

As a kid my father would listen to WCBS-FM all the time. Whenenever we would travel through any of the tunnels in New York the radio would eventually go silent. Then two or three times during the trip through the tunnel, the radio station would come back in for five or ten seconds, then go away. That was the signal reflecting off the walls and intersecting with our car.

Think of FM as a lot like a light bulb. It's mostly line-of-sight, but the same way you can see light from a light bulb in another room, your radio can also "see" the reflection of the FM signal off of stuff.

This is also the reason for "ghosting" on TV signals.

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It depends on the length of the tunnel. In a short tunnel you may not lose either. In a medium sized tunnel you'll lose AM because the waves can't penetrate below ground, though they do run along the ground (groundwave). FM signals will travel farther into the tunnel because of their higher frequency they will bounce off the walls.

As a kid my father would listen to WCBS-FM all the time. Whenenever we would travel through any of the tunnels in New York the radio would eventually go silent. Then two or three times during the trip through the tunnel, the radio station would come back in for five or ten seconds, then go away. That was the signal reflecting off the walls and intersecting with our car.

Think of FM as a lot like a light bulb. It's mostly line-of-sight, but the same way you can see light from a light bulb in another room, your radio can also "see" the reflection of the FM signal off of stuff.

This is also the reason for "ghosting" on TV signals.

That shows what little I know about electronics. All I know how to do is to open the lid, insert a CD, close the lid, then push "play".

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It depends on the length of the tunnel. In a short tunnel you may not lose either. In a medium sized tunnel you'll lose AM because the waves can't penetrate below ground, though they do run along the ground (groundwave). FM signals will travel farther into the tunnel because of their higher frequency they will bounce off the walls.

As a kid my father would listen to WCBS-FM all the time. Whenenever we would travel through any of the tunnels in New York the radio would eventually go silent. Then two or three times during the trip through the tunnel, the radio station would come back in for five or ten seconds, then go away. That was the signal reflecting off the walls and intersecting with our car.

Think of FM as a lot like a light bulb. It's mostly line-of-sight, but the same way you can see light from a light bulb in another room, your radio can also "see" the reflection of the FM signal off of stuff.

This is also the reason for "ghosting" on TV signals.

I think editor used to have his own tv show. You are really Bill Nye the science guy aren't you editor, ADMIT IT ! :D Question, would a HAM radio catch the radio signals he is looking for, or has that been discussed already ?

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