On TVFools FAQ, it lists
1Edge: Single edge diffraction
2Edge: Double edge diffraction
but what's the real difference in layman's terms. I'm not very technical in HD reception.
This is a discussion on TVFool Question within the DTV | HDTV Reception and Antenna Discussion forums, part of the Over-the-Air (Antenna TV) category.
It means there is something between you and the transmitter that blocks LOS (line of sight). Most commonly a hill, a mountain, a building, tree, water tower, etc.
In order to get better reception you have to get your antenna as high as you can, so nothing stands in the way.
That's a great explanation, and I thank you. I'm learning things here I never even thought about before. Who knew this somewhat frustrating would be so educational? <G>
I guess you might need to get someone to make this:
This is one way you can look at it
Comments are my own and not that of the FCC (my employer) or anyone else.
"Ignorance and prejudice and fear walk hand in hand..." - Rush "Witch Hunt"
I like the sketch and the photo, both. They each do a certain amount of illustrating what has been discussed. As for clicking on the link, that's so much work! lol
Cowboy already gave one good thing to try, tilt the antenna up as much as 15 degrees. I have read documented cases of this working in particular if you can see the top of the hill, mountain or building from the antenna. Then it's worth a shot to aim the antenna up toward the top of the hill.
If you can't see what is blocking you can try the angle adjustments, but also try not only raising the antenna but lowering it. Some times going lower you either cancel one of the refracted waves from the edge (see images in link above) or sometimes you just find a spot where the interference add constructively giving a higher signal.
So times as the pictures show move the mast to the other side of the house.
What I like to try is get a 15 ft mast or so and don't mount it but have some help too. Move it around the yard to see if in all places you might mount the antenna if there is a difference in reception.