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COM 1 installation — Identification and location of components
Figure 2
AIAI
Validity : GNS 530 23-12-00 (..) Page 4 JUN 04
 
C. Radio master relays
Radio master relays enable all radiocommunication and radionavigation systems mounted on PL30 radio rack to be electrically supplied.
A radio master switch controls relay operation.
When the radio master switch is set to "ON", the radiocommunication and radionavigation systems are electrically supplied via the de-energization contacts of relays.
When the radio master switch is set to "OFF", or during the engine starting phase, a voltage is applied to the relay coils. The switching of the relay contacts interrupts the electrical power supplied to the systems.
Radio master relays are mounted on a U15 printed circuit, located on the L.H. side forward of PL1 circuit breaker panel.
The radio master switch is located on PL30 radio rack or in variant on the L.H. panel strip of the instrument panel.
Radio master relays are electrically supplied by "BUS 3" bar and protected by CB 60 "RM SWITCH" circuit breaker.
D. "Ground Clearance" assy (option)
"Ground Clearance" assy allows to supply COM 1, NAV 1 installations and GPS1 system when main switch is open.
The components which ensure function are :
- K201 and K202 relays positioned on firewall R.H. side in cabin area.
- K200 switch located at the lower part of PL30 radio rack.
K202 relay is electrically supplied by "BUS 3" bar and is protected by CB 60 "R.M SWITCH" circuit breaker.
K201 relay is electrically supplied by the battery via contacts of K202 relay and K200 switch. It is protected by CB 16 circuit breaker attached to frame No. 4 near starter relay.
4. OPERATION (Figures 4 and 4A)
A. COM1 assy
The radio master switch controls the energization of all the radio NAV and radio COM systems.
Electrical power supply to radiocommunication and radionavigation systems is automatically interrupted during the engine starting phase.
In reception mode, A78 COMM./VOR-ILS/GPS transceiver receives the signals detected by the antenna. Once the useful signal of the carrier wave has been extracted, an audio signal provided by the transceiver is applied at the input of A50 audio control panel. The position of the headset and/or loudspeaker selection buttons assigned to COM 1 (on A50 audio control panel) determines the application of the audio signal, once the latter has been adapted and amplified, to the loudspeaker and / or the headsets.
Press and hold A78 COMM./VOR-ILS/GPS transceiver "C<->" pushbutton to select directly the 121.500 MHz emergency frequency as active frequency.
　
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