I received no responses from the list but thought I would share what we
found on our own locally.

With the assistance of a friend over the radio he was able to figure out the
picture found on the internet is the bottom cover of the radio not the top!

Once you remove the three screws on the bottom of the main unit, with the
front of the radio towards you locate the left hand screw hole for the
bottom cover.

Then to the right side of that and straight down is the jumpers.  By
default, the ts-480 is on "norm" and I reset mine to "DX" my local AM
broadcast stations some 50 miles away went from s9 to 20-30 over s9.  Yes, I
thought it was worth it and the instructions for locating this jumper are
deceiving.  It says in the written text "remove the upper cover" but instead
once upside down the bottom cover is now the top cover.

Anyway, hope that helps.

Brian, k5in