Garmin GPS 400W, Руководство по установке

Страница: 70 / 212

Page 4-16 GNS 400W Series Installation Manual
Rev. G 190-00356-08
4.7 COM/VOR/ILS Audio (GNC 420W and GNS 430W only)
4.7.1 COM/VOR/ILS Audio Function
Activation of COM MIC KEY enables COM MIC AUDIO and causes the transceiver to transmit.
500 COM AUDIO and 500 VOR/ILS AUDIO are 100 mW audio outputs that are intended to drive a
headset or an audio panel.
Momentarily depressing the COM REMOTE TRANSFER button toggles the active and standby COM
frequencies. Momentarily depressing the VLOC REMOTE TRANSFER button toggles the active and
standby VLOC frequencies.
The COM REMOTE TRANSFER input may be used for EMERGENCY operation of the COM
transmitter. If the remote transfer switch is depressed for two seconds, the active COM frequency
changes to 121.50 MHz. Once the emergency frequency is activated through COM REMOTE
TRANSFER, GNS 430W and GNC 420W COM transceivers with COM software version 4.01 or later
ignores inputs from the front panel controls for COM selections only. The pilot may exit this
independent mode—restoring COM selection control to the front panel knobs and buttons—by
momentarily depressing the COM REMOTE TRANSFER switch.
When TRANSMIT INTERLOCK is active, the GNC 420W or GNS 430W COM receiver sensitivity is
decreased. This input is intended to reduce interference from other transmitters in the aircraft. The
TRANSMIT INTERLOCK input should be connected to the PTT input of other transmitters in the
aircraft. If connected to multiple PTT inputs, these connections must include diode isolation or multiple
radios transmit simultaneously.
4.7.2 COM/VOR/ILS Audio Electrical Characteristics
4.7.2.1 COM MIC Key
Pin Name Connector Pin I/O
COM MIC KEY P4002 4 In
This input is considered active if either the voltage to ground is < 1.9 V or the resistance to ground is<
375 . This input is considered inactive if the voltage to ground is 11-33 VDC.
4.7.2.2 COM MIC Audio, INTERCOM MIC Audio
Pin Name Connector Pin I/O
COM MIC AUDIO HI P4002 6 In
COM MIC AUDIO LO P4002 18 In
INTERCOM MIC HI P4002 5 In
INTERCOM MIC LO P4002 17 In
COM MIC AUDIO and INTERCOM MIC each have a 520 AC input impedance and supply the
microphone with a 9 V bias through 620 .
COM MIC AUDIO is set in the factory for 275 mVRMS to modulate the transmitter at 80% nominally.
The microphone gain adjustment is made through Configuration Mode.
When a 125 mV
RMS
signal at 1000 Hz is applied to the INTERCOM MIC input, the level on the COM
AUDIO output is not less than 7.07 VRMS.