TM 1-1510-225-10 3C-33 (1)   Equipment Startup.    The  VIR-32 receiver and  the  CTL -32 NAV control are turned on by rotating the power and mode switch on the NAV control to the ON   position.      After   power   is   applied,   the   CTL-32 displays  the  same  active  and  preset  frequencies  that were present when the equipment was last turned off. (2)   Frequency Selection. Frequency selection  is  made  using  either  the  frequency  select knobs,   or   the   XFR   /   MEM   (transfer/memory   recall switch). Rotation of either frequency select knob increases  or  decreases  the  frequency  in  the  present frequency display.  The larger, outer knob changes the frequency in 1-MHz increments (number to the left of decimal  point).    The  smaller,  inner  knob  changes  the frequency in 0.05-MHz increments. After  the  desired  frequency  is  set  in  the  preset frequency  display,  it  can  be  transferred  to  the  active frequency  display  by  momentarily  setting  the   XFR  / MEM switch to XFR.  At the same time that the preset frequency   is   transferred   to   the   active   display,   the previously active frequency is transferred to the preset display.  The   ACT  annunciator  on  the  control  flashes while the receiver is tuning to the new frequency. NOTE If  the  ACT  annunciator  continues  flashing, it indicates that the receiver is not tuned to the    frequency    displayed    in    the    active display. The CTL-32 has memory that permits storing up to    four    preset    frequencies.        Once    stored,    these frequencies  can  be  recalled  to  the  preset  display  by positioning   the    XFR   /   MEM   switch   to   the    MEM  position.  The storage location (CH 1 through CH 4) for the  recalled  frequency  display  while  the   XFR  /  MEM  switch  is  held  in  the    MEM  position.    All  four  stored frequencies   can   be   displayed   one   at   a   time   in   the preset   display   by   repeatedly   positioning   the   XFR  / MEM  s witch to the   MEM   position.    After  the  desired stored   frequency   has   been   recalled   to   the   preset display,  it  can  be  transferred  to  the  active  display  by momentarily positioning the  XFR / MEM switch to the XFR position. During normal operation, all frequency selections and revisions are done in the preset frequency display.   However, the active frequency can be selected directly as  described  in  the  direct  active  frequency  selection paragraph. (3)   Direct  Active  Frequency  Selection.    The active   frequency   can   be   selected   directly   with   the frequency select knobs by pushing the  ACT button for about   2   seconds.      The   active   frequency   selection mode  is  indicated  by  dashes  appearing  in  the  preset display.    Also,  the   ACT  annunciator  will  flash  as  the frequency select knobs are turned to indicate that the receiver is being re-tuned. NOTE If  the  ACT  annunciator  continues  flashing after  the  frequency  has  been  selected,  it indicates  that  the  receiver  is  not  tuned  to the    frequency    displayed    in    the    active display. To   return   to   the   preset    frequency    selection mode,    push    the    ACT    button    again    for    about    2 seconds. As   a   safety   feature,   the   CTL-32  automatically switches to the active frequency selection mode when a  frequency  select  knob  is  operated  while  the    STO, TEST, or XFR / MEM switches are actuated. (4)   Frequency   Storage.    Up  to  four  preset frequencies can be stored in the memory in the CTL- 32  for  future  recall.    To  program  the  memory,  select the frequency in the preset frequency display using the frequency   select   knobs   and   push   the   STO   button once.  One of the channel numbers (CH 1 through CH 4) will appear in the active display for approximately 5 seconds.  During this time, the channel number can be changed,  without  changing  the  preset  frequency,  by momentarily positioning the  XFR / MEM switch to the MEM  position.    After  the  desired  channel  number  has been selected, push the  STO button again to store the frequency. NOTE When    storing    a    frequency,    the    second actuation of the STO button must be done within     5     seconds     after     selecting     the channel number or the first actuation of the STO   button.      If   more   than   4   seconds elapse, the control will revert to the normal modes  of  operation  and  the  second  store command  will  be  interpreted  as  the  first store command. After  a  frequency  has  been  stored  in  memory, it will   remain   there   until   changed   by   using   the   STO button.    Memory  is  retained  even  when  the  unit  is turned off for an extended period of time. (5)   Self-Test.      During   self-test,   the   VIR-32 provides  VOR,  ILS,  and  marker  beacon  test  outputs.   The    following    paragraphs    provide    the    procedures required    and    the    results    to    be    expected    when performing the self-test.