Page 1-4
GMA 1347D Installation Manual
Revision C
190-00303-21
1.3.2 Electrical Characteristics
Characteristic Specification
Regulatory Compliance
RTCA/DO-160D Environmental Conditions and EUROCAE/ED-14D
Unit Software
RTCA/DO-178B Level C
CLD (Custom Logic
Devices) Compliance
RTCA/DO-254 Level C
Temperature Range
-45
°
C to +70
°
C
Power Requirements
Supply Voltage: 28 VDC
See the Environmental Qualification Form for details on surge ratings and
minimum/maximum operating voltages.
Operating Current: 1.75 amps max at 27.5 V
Altitude 55,000
Feet
Audio Panel
Transceiver inputs: 3
Receiver inputs: 5
Unswitched inputs: 4
Input impedance: 500
Ω
Input isolation: 60 dB minimum
Special functions: Failsafe operation
MASQ
TM
processing
Intercom
Positions: 5 (pilot and 4 passengers per GMA 1347D)
Volume controls: 2 (pilot, passengers)
VOX level controls: 2 (pilot, passengers)
VOX circuits: 5 (one per mic input)
Music inputs (stereo): 2
Music input impedance: 5 k
Ω
Music input level: Less than 500 mVac RMS for full output (typical).
1 Vac RMS MAX (3 Vp-p)
Microphone signal processing: 9 pole characteristic and special cabin
noise band de-emphasis
Intercom isolation modes (-00): 2 (Pilot Isolate, Crew Isolate)
Intercom isolation modes (-20): 4 (Pilot Isolate, Crew Isolate,
Copilot Isolate, All ICS Mode)
Special functions: Recorder with playback (selectable recording of
selected COMs) up to 2.5 minutes of recording time.
Automatic squelch: 5 (one per mic input) pilot selectable between auto
and manual.
Headphone Outputs
Output amplifiers: 2, stereo (pilot, passengers)
Fidelity: Power into 150
Ω
Distortion
50 mW <0.5%
100 mW <5%
Frequency response: Music: 50 Hz to 20 kHz nominal
Aircraft radio: 200 Hz to 6 kHz nominal
ICS mic: (Special cabin noise band de-emphasis)
Speaker Outputs
Outputs selectable: 1, pilot selectable
Output power: 10 watts into 4
Ω
or 8
Ω
, @ any normal supply voltage.
Frequency response: 350 Hz to 6 kHz nominal
Marker Beacon Receiver
Frequency: Crystal controlled at 75 MHz
Sensitivity: LO 1000
μ
V; HI 200
μ
V
Selectivity: 6 dB @ ±10 kHz min, 40 dB @ ±200 kHz max.
Input impedance: 50
Ω
External lamp drive: 125 mA max each output
Other outputs: Middle MKR sense
Special functions
: SmartMute
TM
marker audio muting
