5. Tape Reproducer
A. On GUN/XIA B-2501-B-2505, B-2511, B-2512, and B-2514-B-2516, music for the passenger address system is provided by a magnetic tape reproducer installed in the radio rack. The tape reproducer uses cassettes containing an endless loop of 4-track, 1/4-inch mylar tape providing a playing time of approximately 3 hours. Tape speed is 3-3/4 inches per second. Automatic track switching provides continuous playing.
B. On GUN/XIA B-2509 and B-2510, the prerecorded announcement/boarding music tape reproducer is a 1/2 ATR long shelf-mounted unit located on the E2-1 electronic rack.
(1) The tape reproducer provides prerecorded announcements and high-fidelity monaural audio boarding music while in flight or on the ground. The equipment is designed for remote operation. It employs a standard 1/4-inch wide prerecorded magnetic tape
(3.75 IPS) to provide 3 hours of uninterupted programming.
C. On GUN/XIA ALL EXCEPT B-2501-B-2505, B-2509-B-2512, and B-2514-B-2516, a prerecorded announcement/boarding music tape reproducer is installed on the aft wall of the forward passenger lavatory. Controls for selection and playback of prerecorded announcements or boarding music are on the tape reproducer front face. The prerecorded announcement and music cassette tape is installed through the front of the unit. The audio selected is input to the PA amplifier either as a prerecorded announcement (input No. 3) or boarding music (input No. 4).
D. The tape reproducer is powered by 28 volts dc and 115 volts ac provided through circuit breakers located on panel P6.
6. Attendant's Panels (Fig. 1)
A. The forward attendant's panel contains the integral volume control and on-off switch (GUN/XIA B-2501-B-2505, B-2509-B-2512, and B-2514-B-2516) for the tape reproducer, and a hand microphone used for PA announcements. The aft attendant's panel contains a hand microphone for PA announcements. Both attendant's panels also contain control buttons for the call system and light controls.
5C9
Oct 20/89 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 23-31-0 Page 5
7. Operation (Fig. 2)
A. The passenger address system may be used to communicate with anyone in the passenger compartment. Announcements, sign posted chimes, and music are heard by the passengers over the PSU speakers and lavatory speakers. The crew call chimes are also heard over the attendant's speakers.
B. Music and all announcements are amplified by the PA amplifier. Switching in the amplifier assigns a priority to each input which causes any higher priority input to interrupt any lower priority input. In descending order the priorities are (1) pilot's announcements, (2) attendant's announcements, and (3) prerecorded announcements.
C. A control signal from a PTT switch enables voice audio to be amplified. Sidetone is returned to the pilots through the interphone system. A flight/ground level signal from the oil pressure indicating system establishes the audio level to the speakers. When the airplane is on the ground and engines not running, the level of speaker audio is reduced from that of flight conditions by 6 db.
D. On GUN/XIA B-2501-B-2505, B-2511, B-2512, and B-2514-B-2516, music from the music reproducer is sent to the amplifier when the music switch-volume control on the forward attendant's panel is turned on and adjusted.
E. On GUN/XIA B-2509 and B-2510, the tape reproducer is operated from the MUSIC control on the fwd attendant panel. Rotating the MUSIC control clockwise from the OFF position powers the capstan drive within the tape reproducer. The MUSIC control also controls the boarding music volume and provides the PTT 4 (priority 4) input to the PA amplifier.
中國航空網(wǎng) m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：737 AMM 飛機維護手冊 通訊描述和操作(17)
