TM 1-1510-225-10 3C-15 To   prevent   electromagnetic   radiation   in ramp,   terminal,   taxiway,   or   other   areas occupied by personnel, operate radar only in STANDBY mode. CAUTION Do    not    operate    radar    system,    even    in STANDBY  mode,  without  115-Vac,  400-Hz power  applied  to  the  system.  Without  ac power, the receiver/transmitter/cooling blower will not operate, which could result in circuit damage and/or automatic shutdown. The following paragraphs provide the procedures utilizing  the  capabilities  of  the  NAV  function.    These paragraphs   are   presented   in   sequential   order   from initialization to a composite navigation display. For   the   purpose   of   explanation,   only   NAV   1 controls  and  symbols  are  addressed  in  the  following procedures, except for the composite selection. (a)  Initial Entry. 1.     Turn   on   radar   set   and   external navigation equipment (i.e., compass, DME, radio, etc.). 2.     Set   rotary    switch    to    NAV    and observe     that     disclaimer     notice displays   and   remains   until   any NAV switch is changed. 3.     With  no  selections  made  on  the control unit, the only display is the magnetic  heading  readout.    If,  for some    reason,    the    compass    is inoperative,   the   three   digits   are replaced with dashes. (b)  NAV 1/DES NAV Selection. 1.     Tune  in  desired  VOR  stations  to be used as NAV 1 and  NAV 2. 2.     Place DES NAV 1 / NAV 2 switch to NAV 1. 3.     Press   NAV   1   push   button   and note    that    green    VOR    symbol, distance,  bearing,  and  station  ID readouts display.  If   DES  NAV 1 / NAV 2 switch is placed to  NAV 2, the    VOR    symbol    remains,    but designator readouts disappear. NOTE This  assumes  that  the  station  is  located  in the   area   shown   on   the   display.      The   ID readout  will  not  appear  until  acquired  by the   DME   receiver,   this   may   take   up   to 2 minutes.  (c)  NAV 1 / HDG Selection. 1.     Press  HDG  push  button  and  note that heading line (white) is displayed. 2.     The   selected   heading   line   may now   be   moved   by   rotating   the HDG knob on the HSI. CAUTION The   operator   must   compare   the   heading error line display to the HSI heading bug to ensure  that  the  display  is  in  the  correct quadrant.    The  display  is  correct  only  for heading errors less than 60º. (d)  NAV  1  /  CS  1  Selection.    Press  the CS  1  push  button  and  note  that  a  green  course  line through the NAV 1 station symbol has been added to the display of the preceding paragraph.  Note that the green   CRS,   bearing,   and   station   ID   appear   in   the lower left corner of the display. (e)  NAV 1 / DES Selection. 1.     Rotate    RAD   control   to   position designator symbol to desired radial. 2.     Hold  DES IN / OUT switch in OUT position to move designator symbol to desired position. 3.     Note that designator and connecting line are displayed from the  station  symbol,  and  that  S-D data  and  A-D  data  appear  in  the upper left and lower right corners, respectively, of the display. 4.     The designator may be homed to the  selected  NAV  station  symbol by pressing   HOME  push  button; note  that  when  pressed,  the  S-D readout is now all zeros. WARNING