Section II. COMMUNICATIONS
The communications equipment group consists
of an interphone system, V/UHF, VHF, and HF
communications transceivers, and an ELT.
3C-5. MICROPHONE SWITCHES, MICROPHONE
JACKS, AND HEADSET JACKS.
information on microphone switches, microphone
jacks, and headset jacks.
3C-6. AUDIO CONTROL PANEL T .
a. Description. Individual audio control panels,
part of the radio panel, are provided for the pilot and
copilot. The controls and switches provide for a
selection of transmission on V/UHF, VHF, or HF
transmitters and volume control of communication,
navigation, and interphone audio signals. Figure 3C-1
illustrates the pilots and copilots audio control panel.
b. Controls and Functions.
(1) PILOT/COPILOT AUDIO OFF Switches
Permits monitoring of selected audio regardless of
position of transmitter selector switch.
(a) VHF 1 Permits monitoring of #1
(b) VHF 2 Permits monitoring of #2
(c) HF Permits monitoring of HF
(d) UHF Permits monitoring of V/UHF
(e) NAV 1 Permits monitoring of #1
(f) NAV 2 Permits monitoring of #2
(g) MKR BCN 1 Permits monitoring of
1 and 2 marker beacon audio.
(h) MKR BCN 2 Permits monitoring of
2 marker beacon audio.
(i) DME/TACAN Permits monitoring
of DME / TACAN audio.
(j) ADF 1 Permits monitoring of #1
(k) ADF 2 Permits monitoring of #2
(2) Copilots Transmitter Selector Switch
Controls operation of selected system.
microphone signals to the #1 VHF transceiver.
microphone signals to the #2 VHF transceiver.
(c) HF Permits reception of audio from
the HF transceiver and routes key and microphone
signals to the HF transceiver.
(d) UHF Permits reception of audio
from the UHF transceiver and routes key and
microphone signals to the UHF transceiver.
(e) PA Permits cabin paging.
(3) Copilots AUDIO SPKR / OFF Switch
Determines where selected audio will be heard.
(4) Copilots VOLUME Control Controls
(a) PH Adjusts volume of headset.
(b) SPKR Adjusts volume of cockpit
(c) PA / CABIN ADF Adjusts volume
of cabin speakers.
(5) Copilots VOICE / BOTH / RANGE
Switch and VOL Control Controls both voice and
(a) VOICE Kills range, allows voice
(ADF and VOR).
(b) BOTH Allows both voice and
range (ADF and VOR).
(c) RANGE Kills voice, allows 1020
Hz range tone (ADF and VOR).
(6) MKR BCN 1 and 2 HI / LO / TEST and
VOL Control Switch Selects either sensitivity or