0
Why can AM broadcasts be heard for greater distances under certain conditions?
Wiki User
∙ 14y ago
You can hear AM stations farther away more at night due to a condition known as SKIP, or Skywave Propagation. The propagation of AM radio waves changes drastically from daytime to nighttime. This change in AM radio propagation occurs at sunset due to radical shifts in the ionospheric layers, which persist throughout the night.
During daytime hours when ionospheric reflection does not occur to any great degree, AM signals travel principally by conduction over the surface of the earth. A condition known as "groundwave" propagation.
Useful daytime AM service is generally limited to a radius of no more than about 100 miles, even for the most powerful stations. However, during nighttime hours the AM signals can travel over hundreds of miles by reflection from the ionosphere, a phenomenon called "skywave" propagation.
Basically the AM signal bounces off the ionosphere back to the earth rather than traveling in a direct line. This bounce allows the signal to be heard over vast distances. Amateur radio operators call this talking skip.
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
Why can some am broadcasts be heard for great distances under certain conditions?
AM radio waves bounce off the ionosphere. Favorable weather conditions and lack of sunspot activity enhance the waves' ability to bounce between the earth's surface and atmosphere, allowing the broadcast to travel a greater distance.
Which instrument is used to transmit sound to greater distances?
Audio Amplifier
What effect does surface area have on evaporation?
The greater the surface area, the greater the rate of evaporation under identical atmospheric conditions.
Coulomb's law hold good for all distances greater than 10 to power minus 15 meter why explain?
Coulomb's Law holds under all known circumstances; I am not aware of any exception for small distances. Such an exception might be something that has been speculated, but for the distances tested so far, there is no such exception.
Image form by concave mirror?
A2. A concave mirror is commonly used as a make-up mirror or a shaving mirror. For at close distances, (well inside it focal length) it gives a modest magnification. At distances greater than its focal length, it gives diminished images.
Why can some am broadcasts be heard for great distances under certain conditions?
AM radio waves bounce off the ionosphere. Favorable weather conditions and lack of sunspot activity enhance the waves' ability to bounce between the earth's surface and atmosphere, allowing the broadcast to travel a greater distance.
Are distance between the inner planet greater than the distances between the outer planet?
distances are greater between outer planets
Which instrument is used to transmit sound to greater distances?
Audio Amplifier
Farming allowed people to spend more time?
traveling greater distances.
What are long-haul applications?
It is when transmission distances are greater than five miles
What technology allowed the american indians to hunt from greater distances?
i don't know myself
Is 2 km less than or greater than 2000 m?
They are the same distances
What happens to the force of gravity of the distance increases?
At greater distances, the force of gravity becomes less.
What influences diffusion of ions across the membrane?
distance involved =diffusion at short distances occurs at a greater rate than diffusion at long distances area involved= diffusion over short distance occurs at a greater rate than diffusion over long distances Barriers=thicker barriers slow down rates of diffusion
Does clay sink?
Clay, in fact, does sink at certain conditions. ~Liz http://eragongal44.webs.com
Who found the secrets of infinity?
Cantor found some of them. Specifically, he proved that certain infinities were greater than others.Cantor found some of them. Specifically, he proved that certain infinities were greater than others.Cantor found some of them. Specifically, he proved that certain infinities were greater than others.Cantor found some of them. Specifically, he proved that certain infinities were greater than others.
Why did the Phoenician use the sea for trade?
The Phoenicians use the sea for trade because the alternative - slow 1 ton carts was impossibly over distances greater than 60 km, and their trade distances were in 1,000s of km.
