I know I am suppose to use rg6u or rg59u, but I have a 35' run to do.  I have a roll of rg6, not u.  Am I making a huge mistake not running the u?  It will not cross any power.  I am installing in a huge attic and am going to tie the wire to the rafters away from all the power wires.  Any advice would be greatly appreciated. 
  
-ThaRooster