Avionics Interfaces - Garmin GNS 480 Installation Manual

General Information
Frequency range ............................................ 329.150 to 335.00 MHz
Frequency tolerance ...................................... 0.0008%
Cross modulation products............................ At least 60 dB down
Receiver sensitivity ....................................... -95 dBm typical
Centering error .............................................. RTCA DO-195 two sigma limit: 6.7% of full scale
1.3.8.4 Computation Rates
The tuned active frequency is computed 10 times per second. If the VOR monitor function is activated,
20% of each second is allocated to the monitored frequency, slightly decreasing the active to frequency
computation rate. It is important to note that the monitored frequency is only updated once per second.
1.3.9 A
VIONICS
1.3.9.1 Main CDI (GPS or VHF Nav)
1.3.9.1.1 Deviations / Flags / Annunciators
CDI L/R deviation......................................... ±150 mv full scale (200 Ω load max)
TO/OFF/FROM flag ..................................... ±250 mv, TO/FROM (200 Ω load max)
Nav valid flag................................................ +300 mv for valid indication (200 Ω load max)
Nav superflag ................................................ Vin - 2 volts (minimum) for valid, source capability
VDI up/down................................................. ±150 mv full scale (200 Ω load max)
VDI valid flag ............................................... +300 mv for valid indication (200 Ω load max)
VDI superflag................................................ Vin - 2 volts (minimum) for valid, source capability
GPS/Nav Annunciators ................................. Open collector outputs capable of sinking up to 400
1.3.9.1.2 OBS Resolver
TSO/JTSO compliance ................................. TSO-C40c (DO-196)/JTSO-2C40
Applicable documents................................... RTCA DO-196
Operational class........................................... N/A
Accuracy category......................................... B {-46
Output signal ................................................. 300 Hz ± 2 Hz (rounded square wave)
Output voltage (automatically
adjusted during calibration) .......................... 5 Vpp to 10 Vpp
Input voltage max (calibrated) ...................... 5 Vpp (when OBS is set to maximum)
Resolver voltage gain (loss).......................... 1:1 maximum, 2:1 minimum
Output loading at max voltage ...................... 100 ohms impedance
Accuracy/Resolution..................................... 0.25
1-10
I
NTERFACES
560-0982-01 Rev A
GNS 480 performance: less than 2.0% typical (3.0 mV)
of 400 mA
of 400 mA
mA for turning ON annunciator lamps
o o
C to + 55 C}
o o
rounded to 1 steps
GNS 480 (CNX80) Installation Manual