what's the range of AM radio signals???

[alphatarget1]

I'm in LA right now but holy sh!t i can get the san francisco KGO 810AM all the way in bakersfield!!! I can get some receptions in the mountains too but depends on which part

 

[GoodRevrnd]

There were 6 big ones that were all supposed to reach each other. For instance, I think KFI is supposed to reach some station in Utah. It will depend on how much power they're using to transmit a signal.

 

[Sukhoi]

I've listened to WTAM from Cleveland (50,000 watt transmitter) in Illinois and Washington D.C.

 

The curvature of the earth eventually stops the signal.

See pic here

 

[alphatarget1]

Originally posted by: Roger
The curvature of the earth eventually stops the signal.

doesn't the atmospheric condition bounce some of the signal back onto earth?

so does that mean let's say the space shuttle or space station can receive gazillion of stations?

 

doesn't the atmospheric condition bounce some of the signal back onto earth?

Occasionally yes, but then you end up with a multiplexed signal.

so does that mean let's say the space shuttle or space station can receive gazillion of stations?

I would assume so.

 

[GoodRevrnd]

Originally posted by: kenleung

Originally posted by: Roger
The curvature of the earth eventually stops the signal.

doesn't the atmospheric condition bounce some of the signal back onto earth?

so does that mean let's say the space shuttle or space station can receive gazillion of stations?

I don't think it's the atmosphere, AM waves actually bounce of the stratosphere -- that's why they have such a long range.

 

[NogginBoink]

Originally posted by: GoodRevrnd

Originally posted by: kenleung

Originally posted by: Roger
The curvature of the earth eventually stops the signal.

doesn't the atmospheric condition bounce some of the signal back onto earth?

so does that mean let's say the space shuttle or space station can receive gazillion of stations?

I don't think it's the atmosphere, AM waves actually bounce of the stratosphere -- that's why they have such a long range.

AM transmissions bounce of the atmosphere (the stratosphere is part of the atmosphere) because of the frequency range that the boradcast AM band is in, not because they're AM signals. (In other words, if we broadcast FM at 800 kilohertz, that signal would bounce off the atmosphere, too. It's a function of 800 kilohertz, not AM.)

Your reception of distant stations is likely to be hugely affected by atmospheric conditions. When conditions are right, you can pick up AM broadcasts from way the hell away... like 1000 miles plus sometimes.

 

[jteef]

there are different spectrums that behave differently. Some waves travel along the surface more or less, and some are just line of sight. I forgot the specific scientific terms they use to describe each one. This is how the first trans-atlantic radio conversation worked.

 

[SludgeFactory]

LA to SF during the day sounds very good to me. The reception doesn't really pick up until nighttime.

AM can go a long way, as long as it's a clear channel frequency. You get these maxed-out 50,000 watt stations, and then the FCC makes the local podunk AM stations turn down their signal at night to let the big boys get through. I grew up in Louisiana listening to baseball on KMOX in St. Louis. I could always get San Antonio, usually could get Atlanta, Chicago, and Cincinnati, and sometimes Denver. While living in Atlanta, I could occasionally get a NYC station. Oh yeah, and Mexican stations -- no 50,000 watt limit there. They actually overpower some US stuff. It's heavily dependent on atmospheric conditions too. Summer is tougher because of all the thunderstorms.

My parents put me to bed way too early as a kid, good thing I had a radio.

There are people who do this as a hobby, it's called DX-ing. They get sensitive radio tuners and good antennas and just see how many stations they pick up and from how far away. In the US, they can get AM from Europe, Latin America, the Middle East, and who knows where else.

 

[AlienCraft]

Originally posted by: kenleung
I'm in LA right now but holy sh!t i can get the san francisco KGO 810AM all the way in bakersfield!!! I can get some receptions in the mountains too but depends on which part

Along with the Ionsophere effects there is the effect of "aiming" the transmitted signal by placing the antennas in an array.
I'm trying to find a relevant link to more effecivle explain that.
Will edit it when I find one.

Remember "The Wolfman Jack" Radio show? We used to take AM radios into the Sierra's in Nor.CA. when we went camping w/ The Boy Scouts, (1960's) so we could try to tune in the "skipped" radio signal from DEEP TEXAS!. They actually aimed the antennas so as to cover as much of the US as possible with "skip" signal.

 

[SludgeFactory]

Originally posted by: AlienCraft
Remember "The Wolfman Jack" Radio show? We used to take AM radios into the Sierra's in Nor.CA. when we went camping w/ The Boy Scouts, (1960's) so we could try to tune in the "skipped" radio signal from DEEP TEXAS!. They actually aimed the antennas so as to cover as much of the US as possible with "skip" signal.

Unfortunately I missed out on that (too young), but I've read stories about it. That's one of those things you remember all your life, I'm sure.

I guess the 10 yr olds of today will have fond memories of Napster and Kazaa instead of AM radio.

 

[bernse]

To this day, on a nice evening (usually winter) I can get San Fransisco stations.

I live in Northern Alberta.... about 1300 miles or so I figure.

 

[kranky]

KDKA in Pittsburgh (50,000 watts) reaches 38 states at night.

 

[Hayabusa Rider]

Under the right conditions it is possible to get AM band signals from across the ocean. Signals "bounce" off the ionosphere at night. and may then bounce off the earth and then again off the ionosphere, with the signal making several hops. This is how short wave and ham radio works. AM signals tend to attenuate faster, but with all that power, enough of it gets through to be heard.

 

Originally posted by: Sukhoi
I've listened to WTAM from Cleveland (50,000 watt transmitter) in Illinois and Washington D.C.

My dad used to be able to listen to WTAM early in the mornings (from like 5-7 a.m.) when he lived in Birmingham, AL. Talk about distance!

 

[Eli]

Radio is fascinating.

 

[Chaotic42]

Link

We get WWL radio from New Orleans here in Southern Indiana sometimes. It's nice to hear people speak normally

 

[Sukhoi]

Originally posted by: jumpr

Originally posted by: Sukhoi
I've listened to WTAM from Cleveland (50,000 watt transmitter) in Illinois and Washington D.C.

My dad used to be able to listen to WTAM early in the mornings (from like 5-7 a.m.) when he lived in Birmingham, AL. Talk about distance!

Wow, that is quite a distance! :Q

 

[Aceshigh]

It all depends on the signal strength and direction the antenna is set up in.

AM radio signals will generally travel farther at night than during the day.

For example, AM 740 KTRH in Houston has a 50,000 watt transmitter, and they have the antenna positioned so that their broadcast can generally be heard well at night up and down the Texas coast. There have even been reports of people able to tune in to KTRH all the way down in Belize, which is south of Mexico.

 

[alphatarget1]

Originally posted by: Aceshigh
It all depends on the signal strength and direction the antenna is set up in.

AM radio signals will generally travel farther at night than during the day.

For example, AM 740 KTRH in Houston has a 50,000 watt transmitter, and they have the antenna positioned so that their broadcast can generally be heard well at night up and down the Texas coast. There have even been reports of people able to tune in to KTRH all the way down in Belize, which is south of Mexico.

yeah i can receive KGO in LA right now (night), that's a big w00t!

 

[Analog]

AM radio is not bound by the earth's curvature, but in fact uses the ionosphere to bounce the radio signal. They can go around the earth. Higher frequency signals such as FM, are bound by the earth's curvature.