Beechcraft C-12C Operator And Technical Reference Manual page 244

TM 1-1510-218-10
b. Controls and Functions, Pilot's Audio
Control Panel. Refer to Figure 3A-1.
1. Transmitter Selector Switch
2. VOL Control
3. ICS # 1 / OFF Switches
4. AUDIO SPKR / PHONE Switch
5. AUDIO NORM / EMER Switch
6. FILTER Switches
7. CABIN ADF-1 / OFF / ADF-2 Switch
8. MKR BCN VOL Switch
9. MKR BCN HI / LO Switch
10. HF VOL Control
Figure 3A-1. Pilot's Audio Control Panel
(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 pilot to talk to cabin
occupants.
3A-2
Controls
Permits transmission and
Removes ADF audio from
(2) VOL Control. Controls audio volume.
(3) ICS # 1 / OFF Switches.
monitoring by pilot of selected audio regardless of
position of transmitter selector switch.
(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) 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.
(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.
Either the ADF or VOR switch must be in
the OFF position for the other switch to
function.
(6) FILTER Switches.
Permits
Permits monitoring
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring of
Permits monitoring
/ PHONE Switch.
Audio signal bypasses
NOTE
of
of