TM 55-1510-220-10 keys   in   sequence,   starting   with   "E". Example 20.1' East = E 201. 12. INSERT/ADVANCE pushbutton Press.  Observe pushbutton annunciator extinguishes. NOTE In      above      example,      if      INSERT/ ADVANCE  pushbutton  were  pressed, the   following   normal   display   would appear:   "42'   54.5   N"   and   87'   54.3 "W".    The  extra  precision  values  are added   to   normal   values   and   normal displays are not rounded off. NOTE The   normal   geographic   coordinates must  always  be  loaded  prior  to  extra precision values. NOTE The directions "N" or "S" and "E" or "W" are established during coordinate  entry.    Either  key  may  be used   to   initiate   entry   during   extra precision, loads and the values will be added to extra precision value without affecting direction. NOTE It   is   characteristic   of   the   computer display routine to add 0.2 arc-seconds to   any   display   of   59.9   arc-seconds. The value in computer is as loaded by operator. 13. INSERT/ADVANCE pushbutton Press.    Observe  that  right  data  display indicates last previously inserted altitude, and left data display is blank. 14. To      indicate      the      following   load   is altitude  Press  key  "4"  or  "6".    Observe INSERT/ADVANCE pushbutton annunciator illuminates. 15. To   load   altitude   first   Press   keys   in sequence.    Example:  1230  ft  =  1230. Numbers appear in right data display as keys are pressed. NOTE Altitude inputs are limited to 15,000 feet. 16. INSERT/ADVANCE pushbutton Press. Observe pushbutton light extinguishes. 17. INSERT/ADVANCE pushbutton Press.    Observe  that  left  data  display indicates   last         previously         inserted channel number, and right data display is blank. 18. To      indicate      the   following   load   is channel  number  Press  key  "2"  or  "8". Observe INSERT/ADVANCE pushbutton annunciator illuminates. 19. To  load  channel  number  Press  keys  in sequence.          Example:     109     =     109. Numbers  appear  in  left  data  display  as keys are pressed. 20. INSERT/ADVANCE pushbutton Press.  Observe pushbutton annunciator extinguishes. NOTE Any  number  will  be  accepted  by  the INS;   however   only   stations   with   a channel   number   within   range   of   1 through  126  will  be  used  for  TACAN mixing. NOTE The  channel  number  has  an  implied "X" suffix. NOTE Decimal   points   and   degree   symbols should  be  disregarded  when  reading altitude and channel number displays. 21. INSERT/ADVANCE pushbutton Press.      Observe   station   latitude   and longitude reappear. 22. Repeat   steps   3   through      19   for   each TACAN station. Change 2  3-60