TM 1-1510-223-10 2. UHF  transceiver  164  STBY/NORMAL  switch (pedestal extension, fig. 2-12) - STBY. 3. Function    select    switch    -    MAIN    or    BOTH position, as required. NOTE If function selector is at MAIN setting, only the normal UHF communications will be received. If  selector  is  at.    BOTH  position,  emergency communications   on   the   guard   channel   and normal    UHF    communications    will    both    be received. (2) Transceiver operating procedure. 1. Transmitter-intercom    selector    switch    (audio control panel, fig. 3-1) - 3. 2. Microphone switch - Depress to transmit (3) Preset channel selection. 1. Function selector switch - MAIN. 2. Mode selector switch - PRE 3. Manual    frequency    selector    switches    -    Set frequency to be placed into memory. 4. Preset  channel  selector  switch  -  Set  desired channel number. 5. SET switch - Depress. 3-8. VOICE SECURITY SYSTEM TSEC/KY-58 (COMPLETE PROVISIONS ONLY). Complete  provisions  only  are  provided  for  a  TSEC/ KY-58   voice   security   system.      This   system   provides secure (ciphered) two-way voice communications for the pilot  and  copilot  in  conjunction  with  the  #1  UHF,  VHF- FM   (SINC-   GARS),   and   #2   (BU   VOW)   transceivers. The  system  will  be  located  in  the  left  equipment  rack behind  the  pilot  System  circuits  are  protected  by  the UHF,  VHF-FM,  and  BU  VOW  circuit  breakers  on  the overhead circuit breaker panel (fig. 2-7). 3-9. BACK-UP VOICE ORDER WIRE (BU VOW) (AN/ARC-164). A transceiver identical in type and performance to the UHF    transceiver    (fig.    3-3)    is    located    on    the    left equipment rack, to serve as a back-up voice order wire. The transceiver can only be controlled by the ASF/ACS. Standby   control   is   not   available.      The   transceiver   is selected    on    the    audio    control    panel    (fig.    3-1)    by transmitter-intercom  selector  switch  position  number  5 and by radio audio monitor control number 5.  This set provides for secure communications through interfacing with a voice security system.  The back-up voice order wire  set  is  protected  by  the  7  1/2-  ampere  BU  VOW circuit breaker in the overhead circuit breaker panel (fig. 2-6).    The  back-up  voice  order  wire  shares  an  antenna mounted  on  the  aircraft  belly  with  the  transponder  (fig. 2-1). 3-10. VHF COMMUNICATIONS TRANSCEIVERS (VHF-22B). a. Introduction. The VHF communications transceivers (fig. 3-4), provide airborne VHF communications on 1360 channels from 118.00 through 151.975    MHz,    and    are    operated    by    two    CIL_22 transceiver    control    units,    located    on    the    pedestal extension (fig. 2-12). The    solid-state    transceiver    includes    capture-effect automatic  squelch  to  help  prevent  missed  radio  calls, plus   audio   leveling   and   response   shaping   to   insure audio    quality.        Transmitter    sidetone    comes    from detected  transmitter  signal,  and  is  therefore  a  reliable check of transmission quality.  Each VHF transceiver is powered through its respective circuit breaker, placarded VHF # 1 or VHF # 2, located on the overhead circuit breaker panel (fig. 2-7). b. VHF  Transceiver  Operating  Controls  (VHF-  22B). All operating controls for the transceivers are located on the CTL22 transceiver control units and on the FMN/AM alternate communication switch panel (pedestal extension, fig. 2-12). (1) Active    frequency    display.        Displays    the active  frequency  (frequency  to  which  the  transceiver  is tuned) and diagnostic messages. (2) Transfer/memory  switch.    This  switch  is  a three-position    spring-loaded    toggle    switch    placarded XFR/   MEM,   which   when   held   to   the   XFR   position, causes the preset frequency to be transferred up to the active  display  and  the  transceiver  to  be  returned.    The previously active frequency will become the new preset frequency  and  will  be  displayed  in  the  lower  window. When this switch is held to the MEM position, one of the six stacked memory frequencies will be loaded into the preset  display.    Successive  pushes  will  cycle  the  six memory frequencies through the display (...2,3,4,5,6,1,2,3...). (3) Store  switch.    This  switch,  placarded  STO, allows  up  to  six  preset  frequencies  to  be  selected  and entered into the control unit's memory.  After presetting the  frequency  to  be  stored,  push  the  STO  switch  The upper window displays the channel number of available memory  (CH  1  through  CH  6)  while  the  lower  window continues  to  display  the  frequency  to  be  stored.    For approximately 5 seconds, the MEM switch may be used to advance through 3-7