TM 1-1510-218-10   3C-7 (2)   Interphone   Operating   Procedure   (Voice- Actuated Continuous Microphone Availability). 1.   Pilot's and copilot's interphone switches – Set to INTPH. 2.   Pilot's  and  copilot's  speaker  switches – Set to OFF. 3.   Begin speaking into headset microphone to actuate intercom operation. 4.   VOLUME controls – Adjust audio level in headphones. (3)   Interphone  Operating  Procedure  (Press- To-Talk Microphone Operation). 1.   Microphone   switch   –   Press   to   first level then speak into microphone. OR 2.   Pilot's and Copilot's Transmitter Selector Switches – INTPH. 3.   Microphone   Switch   –   Press   second level then speak into microphone. OR 4.   Copilot – Press foot -switch then speak into microphone. (4)   Navigation  Aid  and  Receiver  Monitoring Procedure. 1.   Receiver   Audio   Monitor   Switches   – Set  switches  of  desired  receivers  to on "up" position. 2.   VOLUME   Control  –  Adjust  individual receiver being monitored. (5)   Transmitting Procedure. 1.   Transmitter  Selector  Switch   –  Set  to desired transmitter. 2.   Microphone Switch – Press. 3.   Speak into microphone. d.  Emergency Operation. 1.   AUDIO  EMER  /  NORM Switch   –  Set  to EMER. 2.   Pilot/Copilot     Audio     Switches     –     OFF.   Audio will bypass the amplifiers and will be applied   directly   to   the   headsets.      Turn OFF    unused    receivers    or    turn    down individual  VOLUME  controls  to  eliminate undesired audio. 3C-8.  V/UHF    COMMUNICATIONS    TRANSCEIVER (AN/ARC-210(V)). a.   Description.  The AN/ARC-210(V) Communication System provides multimode voice and data  communications  in  either  normal  or  jam-resistant modes via Line Of Sight (LOS).  It operates in the 30- 400 MHz frequency range (VHF/UHF) and on AM and FM single channel operation. b.  Table 3C-1 lists the frequency coverage and modulation available with the AN/ARC-210(V) Radio. Table 3C-1.  AN/ARC-210(V) Frequency Coverage and Modulation FREQUENCY RANGE (MHz) MODULATION 30-88 FM Clear/Secure Voice/Data 108-136 AM Clear/Secure Voice/Data (108-118 MHz receive only) 136-156 FM Clear/Secure Voice/DATA 156-174 FM – (Maritime) 225-400 AM/FM   –   Voice/Data   HAVE QUICK and SATCOM 121.5 (Guard) AM 243.0 (Guard) AM of FM c.   Refer  to  Paragraph  3C-25,  Automatic  Flight Control, for operating procedures. 3C-9.  VHF     COMMUNICATIONS    TRANSCEIVERS (VHF-22C). a.   Introduction.        The    VHF    communications transceivers provide airborne VHF communications on 772 channels from 118.00 through 136.990 MHz, and is operated by two CTL -22 transceiver control units. 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 circuit breaker panel.