737-300/400/500
MAINTENANCE MANUAL
CONTROL CABIN
ATT/GND CREW CALL PANEL (P5)
AURAL WARNING UNIT (P9)
SERVICE INTERPHONE SW (P5)
CAPT AUDIO SELECTOR PANEL (P21)
F/O AUDIO SELECTOR PANEL (P23)
OBSERVERS AUDIO SELECTOR PANEL (P5)
VOICE RECORDER CONTROL PANEL (P5)
VHF COMM 1 CONTROL (P8)
VHF COMM 2 CONTROL (P8)
ELECTRONIC EQUIPMENT RACKS
VHF COMM 1 TRANSCEIVER (E2-1)
VHF COMM 2 TRANSCEIVER (E2-1)
AUDIO ACCESSORY UNIT (E2-1)
TAPE REPRODUCER (E2-1)
PASSENGER ADDRESS AMPLIFIER (E2-1)
HF-1 TRANSCEIVER (E2-3)
HF-2 TRANSCEIVER (E2-3)
SELCAL DECODER (E2-2)
Communications Equipment Locations
Figure 1
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
HF COMMUNICATION SYSTEM - DESCRIPTION AND OPERATION
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1. General_______
A. Two high frequency (HF) communication systems are installed in the airplane.
B. The high frequency (HF) communication system provides amplitude modulated and single sideband voice communication between airplane and ground or other airplane. The HF communication system is referred to as the HF system. Communication is in the 2.000 to 29.999 MHz frequency range on any of 28,000 channels at 1 kHz spacing. Propagation characteristics of the HF band are most suitable for long distance communications.
C. Each HF system includes an HF control panel, HF transceiver, HF antenna coupler, coupler status annunciator panel, and HF antenna. The HF control panel is installed on the aft electronics control stand. The flush-mounted HF antenna is part of the vertical fin leading edge. The HF antenna coupler is installed inside the vertical fin leading edge approximately under the HF antenna. The HF transceiver is installed in the main equipment center on electronic equipment rack E2, E3, or E5 or in the aft electronic equipment rack E6. The component locations are shown in figure 1.
D. The coupler status annunciator panel (if installed), is mounted between the E1 and E3 racks or on electronics equipment rack, E6.
E. On airplanes with the Gables-3852 HF dual control panels installed, each HF system shares a single HF antenna and HF control panel.
F. In dual HF system installations, the HF-1 and HF-2 systems share the HF antenna.
G. The HF control panel enables the desired communication channel to be selected and the HF system to be turned on or off. Sidetone is connected to the HF system audio switch in the flight interphone system. The HF antenna coupler matches the characteristic antenna impedance to the impedance of the HF transceiver at the particular frequency on which the HF system is operating. The tuner control unit and tuner will automatically keep the voltage standing wave ratio (VSWR) to a level between 1.3 and 1.0 thus assuring good power transfer. Communications are completed through the flight interphone system (AMM 23-51-00/001).
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本文链接地址：737-300 400 500 AMM 飞机维护手册 通讯 COMMUNICATIONS(5)
