That adjustment should come under the heading of "area's" which of course should be set as "area US" as I suspect that its either sitting at "area SA" or "area EU" as these are the settings that give different spaces between the stations. Access to these settings being obtained by "holding in" the "Select" button which allows entering the PSM menu, then selecting "area" by using the up / down arrows button, then selecting "area US" by turning the knob clock or anti-clock, finally pressing select again to store.