DXING from Mount Washington, NH

[BRNout]

Atop a mountain near Palm Springs, Ca I had a clear shot at AMs from San Diego, LA, and even as far as Phoenix.
Lots of low powered AM stations came in at this location. These same stations were not heard on the desert floor.
Another time I was parked high above Laguna Beach where I could hear San Francisco's KGO, KCBS, & KNBR clearly around 1PM.
The ocean was a factor, but I could not hear these stations when I was down lower near the beach.

Don't get me wrong: being on top of a mountain helps AM reception by removing physical obstacles from the equation. But, it also doesn't give the spectacular results that you see with FM because of the differences in how the bands propagate.

A great example is right here in this thread in that the poster couldn't get New York AMs from Mt. Washington. Well, at a much farther distance, NY AMs come in well along the Outer Banks of North Carolina. You still have the ground conductivity to deal with on a mountaintop - and conductivity in northern New Hampshire is not very good.

 

[radioman148]

Atop a mountain near Palm Springs, Ca I had a clear shot at AMs from San Diego, LA, and even as far as Phoenix.
Lots of low powered AM stations came in at this location. These same stations were not heard on the desert floor.
Another time I was parked high above Laguna Beach where I could hear San Francisco's KGO, KCBS, & KNBR clearly around 1PM.
The ocean was a factor, but I could not hear these stations when I was down lower near the beach.

Don't get me wrong: being on top of a mountain helps AM reception by removing physical obstacles from the equation. But, it also doesn't give the spectacular results that you see with FM because of the differences in how the bands propagate.

A great example is right here in this thread in that the poster couldn't get New York AMs from Mt. Washington. Well, at a much farther distance, NY AMs come in well along the Outer Banks of North Carolina. You still have the ground conductivity to deal with on a mountaintop - and conductivity in northern New Hampshire is not very good.

Agreed. FM has a major advantage with height no doubt. My point was just that if ground conductivity is the same--etc, AM can also be helped by height to some degree. Clearly not to the degree that FM reception can be improved.

 

[phil]

What receiver were you using? A car radio? Battery powered portable? Just curious.

 

[K4WRF]

Atop a mountain near Palm Springs, Ca I had a clear shot at AMs from San Diego, LA, and even as far as Phoenix.
Lots of low powered AM stations came in at this location. These same stations were not heard on the desert floor.
Another time I was parked high above Laguna Beach where I could hear San Francisco's KGO, KCBS, & KNBR clearly around 1PM.
The ocean was a factor, but I could not hear these stations when I was down lower near the beach.

Don't get me wrong: being on top of a mountain helps AM reception by removing physical obstacles from the equation. But, it also doesn't give the spectacular results that you see with FM because of the differences in how the bands propagate.

A great example is right here in this thread in that the poster couldn't get New York AMs from Mt. Washington. Well, at a much farther distance, NY AMs come in well along the Outer Banks of North Carolina. You still have the ground conductivity to deal with on a mountaintop - and conductivity in northern New Hampshire is not very good.

Agreed. FM has a major advantage with height no doubt. My point was just that if ground conductivity is the same--etc, AM can also be helped by height to some degree. Clearly not to the degree that FM reception can be improved.

Receiver elevation at a distance from the transmitter is no advantage at medium frequencies. Mountainous terrain exhibits poor to moderate and very erratic variances in soil conductivity. Sand on the other hand exhibits the worst admittance.