The cache is not located at the posted coordinates. Solve the puzzle below to get the real coordinates.
This puzzle was for the Seattle FTF Bell.
To solve this puzzle, you need to insert both a letter and a number in each square. 1 to 9 and A to I for the 9x9, J to M and 1 to 4 for the 4x4. The numbers and letters must follow the usual Sudoku rules. In addition each pair must appear once and only once. The tables below the grids are to help you keep track of the pairs you've identified so far. When you are done, the string of letter number pairs will give you the final coordinates!
Congratulations to PepsiPrincess, lamoracke and crs98 on the co-FTF!