Beechcraft C-12C Operator And Technical Reference Manual page 245

(a) FILTER V / OFF. Filters out voice on
ADF and VOR audio.
(b) FILTER R / OFF.
identification code on ADF-2 and VOR audio.
(7) CABIN ADF-1 / OFF / ADF-2 Switch.
Selects desired ADF audio for use with cabin
speakers.
(a) ADF-1. Selects ADF-1 audio for use.
(b) OFF.
cabin speakers.
(c) ADF-2. Selects ADF-2 audio for use.
(8) MKR BCN VOL Switch.
volume of marker beacon audio.
(9) MKR BCN HI / LO Switch. Selects either
high or low marker beacon sensitivity.
(10) HF VOL Control.
marker beacon audio.
c. Controls and Functions, Copilot's Audio
Control Panel. Refer to Figure 3A-2.
(1) Transmitter Selector Switch.
operation of selected system.
(a) HF. Permits reception of audio from
the HF transceiver and routes key and microphone
signals to the HF transceiver.
(b) UHF. Permits reception of audio from
the UHF transceiver and routes key and microphone
signals to the UHF transceiver.
(c) VHF-1. Routes key and mic signals
to the #1 VHF transceiver.
(d) VHF-2. Routes key and mic signals
to the #2 VHF transceiver.
(e) INTPH.
reception of interphone signals.
(f) CABIN.
cabin speakers and allows the copilot to talk to cabin
occupants.
(2) VOL Control. Controls audio volume.
(3) ICS # 2 OFF Switches.
monitoring by copilot of selected audio regardless of
position of transmitter selector switch.
Filters out
Removes ADF audio from
Adjusts the
Adjusts volume of
Controls
Permits transmission and
Removes ADF audio from
Permits
(a) HF. Permits monitoring of HF audio.
(b) UHF.
UHF audio.
(c) VHF 1.
VHF-1 audio.
(d) VHF 2.
VHF-2 audio.
(e) VOR 1.
VOR-1 audio.
(f) VOR 2.
VOR-2 audio.
(g) ADF 1.
ADF-1 audio.
(h) ADF 2.
ADF-2 audio.
(i) INTPH.
interphone audio.
(4) FILTER Switches.
Either the ADF or VOR switch must be in
the OFF position for the other switch to
function.
(a) FILTER V / OFF. Filters out voice on
ADF and VOR audio.
(b) FILTER R / OFF.
identification code on ADF-2 and VOR audio.
(5) AUDIO NORM / EMER Switch. Controls
routing of received audio signals.
(a) NORM. Routes audio signal through
amplifier to speaker or headphone.
(b) EMER.
amplifier. Applies audio signal to headphone only.
(6) AUDIO SPKR
Determines where selected audio will be heard.
(a) SPKR. Allows selected audio to be
heard via the speaker.
(b) PHONE. Allows selected audio to be
heard via the phone.
TM 1-1510-218-10
Permits monitoring
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring
NOTE
Filters out
Audio signal bypasses
/ PHONE Switch.
of
of
3A-3