[TowerTalk] Snow and rain attenuation

[Jim Brown]

On Mon, 31 Oct 2005 16:32:50 -0800, Bob Nielsen wrote:

>There are frequencies where there is a resonance with water molecules  
>which causes a quite high attenuation, even without rain or snow. 

My DirecTV receiver will die briefly during very heavy rain. I don't know 
what frequencies they're using, but it isn't a very big dish, so there 
probably isn't a lot of gain margin. Remember -- it's a digital "cliff 
effect" -- that is, the signal fades gradually, but you don't notice it 
until the level drops so much that the system starts losing so many bits 
that it can no longer do error correction (or assemble enough bits to make 
a picture). 

Jim K9YC