Remove non-ASCII characters from file

There was a text file that contained non-ASCII characters that acted like spaces within the file, so I used the tried and true dos2unix command to attempt to clean the file; however, the characters remained.  With hundreds of lines to correct, manually deleting the offending areas of the file was not an option.  A real solution is needed. Once again, to the rescue.

The following command worked exactly as expected.

sed -i 's/[\d128-\d255]//g' FILENAME

Other solutions offered; however, not tested by me.

perl -i.bk -pe 's/[^[:ascii:]]//g;' filename
sed -i 's/[^a-zA-Z 0-9`~!@#$%^&*()_+\[\]\\{}|;'\'':",.\/<>?]//g' FILE