TM 1-1510-225-10 3B-2 Section II.  COMMUNICATIONS 3B-4.  COMMUNICATIONS EQUIPMENT GROUP DESCRIPTION. The  communications  equipment  group  consists of   an   intercom   system   connected   to   a   dual   audio control  panel  serving  both  the  pilot  and  copilot,  which interfaces with VHF, SATCOM V /UHF, HF transceivers,   and   provides   reception   of   audio   from VOR,    Localizer,    Marker    Beacon,    DME    and    ADF receivers.    Also  included  is  the  ELT,  Voice  Cockpit Recorder  OSA , and Flight Data Recorder OSA . 3B-5.  MICROPHONES, SWITCHES, AND JACKS. a.   Description.      The  communication  group  is comprised   of   an  interphone  system  connected  to  a dual audio control panel, with separate controls for the pilot and copilot that interface with VHF SATCOM and HF   communication   units.      HF   radio,   cockpit   voice recorder,  and  flight  data  recorder  equipment  are  not installed in ANG aircraft.  Hand held boom and oxygen mask microphones can be utilized in the aircraft. b.  Controls and Functions.  (1)   Control     Wheel     Microphone     Switches.   The  pilot  and  copilot  are  each  provided  with  control wheel  microphone  switches,  placarded   MIC,  located behind    the    outboard    handgrip    of    their    respective control  wheels,  Figure  2-22.    When  the  control  wheel microphone switches are pressed, voice audio signals from   the   respective   microphones   are   routed   to   the transmitter    selected    by    the    respective    transmitter selector  switch,  located  on  the  audio  control  panel, Figure 3B-1. (2)   Cockpit Floor Foot-Operated Microphone Switch.    The  copilot  is  provided  with  a  foot-operated microphone   switch,   placarded   MIC,   located   on   the cockpit  floor,  forward  of  his  respective  seat  position.   Pressing  the  foot-operated  microphone  switch  routes audio  signals  to  the  device  selected  by  the  copilot’s transmitter selector switch located on the audio control panel. (3)   MIC NORMAL / OXYGEN MASK Switch.   This    switch    is    located    on    each    pilot’s    respective outboard subpanel and selects microphone in OXYGEN  MASK or   MIC   NORMAL  selects  boom  or hand held microphone. (4)   Microphones    Jacks.        Two    jacks    are located in the side walls of the aircraft to the left of the pilot  and  to  the  right  of  the  copilot.    Hand   held mike uses only the  MIC jack.  Boom mikes use both jacks, to include MIC  HEADSET jack. 3B-6.  AUDIO CONTROL PANELS. a.   Description.      A   dual   audio   control   panel located  on  the  instrument  panel  serves  both  the  pilot and  copilot.    Its  respective  2-ampere  circuit  breaker, placarded    PILOT     AUDIO    and     COPILOT     AUDIO, located   on   the   right   sidewall   circuit   breaker   panel powers each audio control panel. b.  Audio Control Panel Controls and Functions.   Refer to Figure 3B-1. (1)   Pilot’s  COMM  1  Switch  –  Selects  No.  1 very high frequency receiver. (2)   Pilot’s  COMM  2  Switch  –  Selects  No.  2 very high frequency receiver. (3)   Pilot’s HF Switch – Selects high frequency receiver. (4)   Pilot’s  MBND   RADIO   Switch   –  Selects ARC-210 radio transmitter. (5)   Pilot’s   NAV   1   Switch   –  Selects  No.  1 VOR audio. (6)   Pilot’s   NAV   2   Switch   –  Selects  No.  2 VOR audio. (7)   Pilot’s  MKR  BCN  1  Switch  –  Receives audio from No. 1 marker beacon. (8)   Pilot’s  MKR  BCN  2  Switch  –  Receives audio from No. 2 marker beacon. (9)   Pilot’s   DME   Switch   –   Receives   DME audio. (10)   Pilot’s    ADF    Switch    –    Receives    ADF audio. (11)   Copilot’s COMM 1 Switch  – Selects No. 1 very high frequency receiver. (12)   Copilot’s COMM 2 Switch  – Selects No. 2 very high frequency receiver. (13)   Copilot’s     HF     Switch     –     Selects     high frequency receiver.