(6)  
Remove electrical power if no longer required (AMM 24-22-00/201).

 EFFECTIVITY

 
 ALL  09 Page 403  Oct 25/9734-32-01
 MARKER BEACON SENSITIVITY CONTROL - REMOVAL/INSTALLATION
________________________________________________________
 1.  General
_______
 A.  The marker beacon sensitivity control is mounted on the first officer's main instrument panel.
 2.  Referenced Procedures
_____________________
 A.  31-10-00, Panels - Description and Operation
 3.  Remove Sensitivity Control
__________________________
 A.  On ALL ATLAS airplanes EXCEPT AF ALL,
 open MKR BCN circuit breaker on circuit breaker panel P7.

 B.  On AF ALL, open MKR BCN and MKR BCN-1 circuit breakers on circuit breaker panel P7.
 C.  Rotate instrument panel down to gain access to rear of
 sensitivity control (Ref 31-10-00).

 D.  Record relationship of wiring and terminals of control.
 E.  Disconnect wiring from back of control.
 F.  Remove retainer from front of control and remove control.
 4.  Install Sensitivity Control
___________________________
 A.  Position control through cutout on instrument panel and fasten retainer.
 B.  Connect wiring to terminal.
 C.  Install instrument panel (Ref 31-10-00).
 D.  Close circuit breakers opened in steps 3 A. and 3 B.
 EFFECTIVITY

 
 ALL  03 Page 401  Jul 25/7834-32-03
 LOW RANGE RADIO ALTIMETER SYSTEM - DESCRIPTION/OPERATION
________________________________________________________
 1.  General
_______
 A.  The low range radio altimeter (LRRA) system supplies vertical position information for use by the pilots during approach and landing phases of flight operation. The LRRA system provides an accurate measurement of absolute altitude (height above terrain) from 2500 feet to touchdown. Flag alarm, dc altitude, and vertical terrain clearance (altitude trip) outputs are available for use by other systems.
 B.  Three systems are installed in the airplane. Systems 1 and 2 consist of a receiver-transmitter, height indicator, DH light and rising runway display on an attitude director indicator, transmit antenna, and receive antenna. System 3 consists of a receiver-transmitter, failure annunciator, transmit antenna, and receive antenna. Location of components is shown on Fig. 1.
 C.  Power distribution to the LRRA equipment and the interface between the LRRA systems and other airplane systems is shown on Fig. 2.
 2.  Receiver-Transmitters
_____________________
 A.  Collins 860F-4 Receiver/Transmitters
 (1)  
The receiver-transmitters are located side by side in center equipment center E9. A test connector with protective cover is located on the front panel. Two locking lugs secure the unit to its mount. A handle for carrying the unit is provided on the front panel.

 (2)  
A single TEST/STATUS switch/indicator on the receiver/transmitter front panel provides self-test facilities.

 3.  Antennas
________
 A.  The antennas are linearly polarized horns. Two identical antennas are used in each system; one for transmitting and one for receiving. The antennas are flush-mounted on the lower fuselage of the airplane. The three transmit and three receive antennas are located at body station 913 and 933, respectively. System 1 antennas are to the left of the fuselage centerline. System 2 antennas are on the fuselage centerline. System 3 antennas are to the right of the fuselage centerline. Coaxial cables connect the antennas to the receiver-transmitters.
 4.  Height Indicators
_________________
 A.  A height indicator (HI) with either a circular scale altitude dial (Collins 339H-1) or a vertical scale altitude tape (Collins 339H-2) is provided on each pilot's front instrument panel. The height indicator provides a visual display of absolute altitude (height above terrain).
 B.  Collins 339H-1 Height Indicator
 (1)  The operating controls and indicators consist of a DH control knob, DH index, DH light, test pushbutton switch, dial, altitude pointer, pointer mask, and warning flag. The circular dial is graduated from -20 to 2500 feet. The graduation is linear from -20 to 500 feet and logarithmic from 500 to 2500 feet. Self test of the LRRA system is initiated by pressing the TEST pushbutton.
 EFFECTIVITY AZ ALL; IB 406-499  
  CONFIG  05 Page 1  Aug 25/88

34-33-00
TRANS/REC TRANSMITSEE B NO. 1, 2 AND 3 ANTENNA
　
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