TM 1-1510-218-10 3C-14 3.   Mode     Selector     Switch –     Set emission    mode    (USB,    LSB,    or AM). 4.   STO Switch – Press. NOTE A   flashing   TX   will   appear   in   the   display window,   but   should   be   ignored   since    a receive only frequency is being set. If  another  channel  is  to  be  set,  the  cursor must be stowed before a new channel can be  selected.    Use  the  smaller  concentric knob  to  select  the  channel  and  repeat  the steps for selecting a new frequency. 5.   To  return  to    an  operating  mode, push the PGM switch. (b)   Simplex. 1.  Cursor  –  Stow  if  a  flashing  digit  is present. 2.  Frequency/Channel Switch – CHAN (in). 3.  PGM Switch   –  Press,  check  that PGM annunciator in the display is illuminated. 4.  Tuning Knobs  – Select channel to be preset and desired frequency. 5.  Mode   Selector   Switch    –   Select emission    mode    (LSB,    USB,    or AM). 6.   STO Switch  –  Press  and  release twice.    The  first  press  of  the  STO button stores the frequency in the receive   position   and   the   second press  stores  the  same  frequency in    the    transmit    position.        The second     push     also     stores     the cursor. 7.   If  another  channel  is  to  be  reset, use the smaller concentric knob to select the channel and repeat the steps for selecting a new frequency.        The    cursor    will    be automatically stowed.  To return to an operating mode, push the PGM button again. (c)   Semi-Duplex. 1.  Cursor  –  Stow  if  a  flashing  digit  is present. 2.  FREQ/CHAN Switch – CHAN (in). 3.  Mode     Selector     Switch –     Set emission    mode    (USB,    LSB,    or AM). 4.  PGM Switch   –  Press,  check  that PGM annunciator in the display is illuminated. 5.  Tuning Knobs  – Select channel to be  preset,  operating  mode  (USB, LSB,  or  AM),  and  desired  receive frequency. 6.   STO  Switch  –  Press  and  release once. 7.   Transmit Frequency – Set. 8.   STO   Switch   –   Press   again.      If another  channel  is  to  be  preset, use the smaller concentric knob to select the channel and repeat the steps. 9.   To  return  to  an  operating  mode, push the PGM button. NOTE The  mode  for  each  channel  (LSB,  USB,  or AM) is stored along with the frequency.  If the    m ode    is    changed,    the    system    will receive  and  transmit  in  the  mode  selected for transmit. 3C-11.  EMERGENCY LOCATOR TRANSMITTER (DM ELT8.1). a.   Description.        An    automatic    or    manually activated    Emergency    Locator    Transmitter    (ELT)    is located   on   the   right   side   of   the  aft  fuselage.    The associated   antenna   is   mounted   on   top   of   the   aft fuselage  at  the  same  location,  Figure  2-1.  An access hole  with  a  spring-loaded  cover  is  located  in  the  right fuselage  skin  adjacent  to  the  transmitter,  enabling  a downed  pilot  to  manually  initiate,  terminate,  or  reset the ELT to an armed mode.  Self-contained batteries provide  operation  for  a  minimum  of  48  hours   T1  and 50 hours T2 at 200 milliwatts.  The transmitter contains an  impact  G  switch  that  automatically  activates  the transmitter following a 3-7G impact along the flight axis of the airplane T1 and a 10 G impact along any axis of the aircraft  T2..  When activated, it will simultaneously radiate  omnidirectional  RF  signals  on  the  international