I tried to convert a drw file which I had drawn 1:1 on a sheet size of 8m x 6m, for manufacturing purposes and the manufacturer asked for a PDF file,to a PDF  file but it would not work and came up with a message that the maximum sheet size is 200 inches x 200 inches ( apprx. 5m x 5m ).

When I tried to decrease the scale I lost relationships between annotations and dimensions. Having to change all this was not practical with a large number of drawings.