 The National Radio Astronomy Observatory (featured in the film) has  a club station which, with the permission of Reber, had acquired his  old call sign "W9GFZ" earlier in 1997. Zemeckis, learning of this  tribute, planned to use the same call sign for Arroway in the movie.  However, in the end "W9GFO" was used instead. While viewing the film  after release, David Wilson of the Internet recognized this call  sign as that of his father Robert (Bob) Wilson from the late 1930s.  W9GFO and K4WLD are currently assigned to ham radio operators in the  USA.