Join Date: Jul 2008
Location: North of the GTA
As above, 200' should require NO amplification at all, it is well within the specs.
I would question the type of RG6 line used underground, is it the correct 'flooded' type of cable.? If not then even tree roots can damage the outer sheathing and allow water into the cable.
As you seam to say it is a recent issue, I would be looking for corrosion somewhere, including moisture ingress into the cable or a hidden connection.