40 meters

Hi All I have a line of trees above my house approx 30 yards linear up with an elevation change of approx 6-8 feet from the foundation of my house to the line of trees. The tallest tree is about 100 feet high in the air. My question is : Can I place the center dipole 50-90 feet up in that tree...

I would like to know the mode in which Broadcast shortwave signals are transmitted in, beceause I have the Eton/Grundig mini 300PE( http://www.etoncorp.com/product_card/?p_ProductDbId=6289 ). This is basic shortwave receiver but the "41meter" band fully encompasses the 40 meter amateur band...