(b)
Set MODE selector switch to self-test position and set T/R ATTEN control to 25 DB. Observe that meter indicates to the right of RECHARGE. If meter indicates to the left of RECHARGE, the battery must be recharged before tester is used.
(c)
To calibrate the R-F OUTPUT, set MODE SELECTOR to SELF-TEST. Position CALIBRATE OUTPUT-BATTERY VOLTAGE switch in calibrate output position, and adjust OUTPUT to obtain a red-line indication on meter.
(d)
To self-test, set MODE SELECTOR switch to SELF-TEST, and set T-R ATTEN control to 25 DB. Observe that IDENT flag appears. 1) Set code selector to 0000 code. Observe that CODE and
IDENT flags appear in steady state. 2) Set code 7777. Observe that CODE and IDENT flags appear in steady state. 3) Set code 7773. Observe that CODE flag blinks; IDENT flag appears in steady state. 4) Set code 0004. Observe that CODE flag blinks; IDENT flag appears in steady state.
(2)
Place 476X-3 ramp test set at a distance of between 40 and 50 feet from ATC antenna in a position easily visible from the cockpit, and with an unobstructed radiation path betwen tester and antennas.
(3)
Orient tester such that inside of opened cover (antenna element) faces airplane antennas.
(4)
Position controls on test set as follows:
Function Selector - A-B-C R/T ATTN DB - 10 Code Switches - Any desired code.
(5)
Ensure ATC system and altitude source (altimeter or CADC) circuit breakers on panel P7 are closed.
CAUTION: IN THE FOLLOWING TEST DO NOT SELECT CODES 7500, 7600-7677,
_______ AND 7700-7777. THESE ARE EMERGENCY CODES.
E. Test ATC System Using Collins 476X-3 Test Set
(1) Perform ATC system operational test procedure provided in
AMM 34-53-00, ATC System - Adjustment/Test.
EFFECTIVITY AF ALI ALL; DLH ALL; IBE ALL;
AF SAB ALL; AF, AT,MD, GN, AF AND VM WITHOUT AEB 34-587 CONFIG 1 AF AND 34-607 02 A Page 502
Oct 25/96
34-53-00
(2) Position controls on ATC control panel as follows: ALT RPTG/REPORT - OFF Code Switches - Same as on test set
Function Selectors- Activate appropriate ATC system for normal operation in mode A.
Observe test set, verify code flags appear each time mode A flag appears.
NOTE:____ The presence of a strong signal from a nearby ground beacon may override the test signal from the 476X-3 and produce incorrect test results.
(3) Change test code selection on both ATC control module and test set to test code compliment. Compliment of test code is 7777 minus test code being used. This checks the full code capability of the transponder under test.
EXAMPLE:_______ If test code being used is 0340, the compliment is:
7777
-0340_____ 7437 Compliment
(4) (5) (6) During time interval when mode A flag is in view, activate IDENT on ATC control panel. Verify a blinking indication of both IDENT and code flags on test set.On ATC control module, select LO SENS. Observe test set, verify mode and code flags appear.Test altitude reporting as follows: (a) On ATC control panel, select ALT RPTG/REPORT and ALT source. (b) Connect air data test set to pitot-static system (AMM 34-11-00). (c) Adjust altimeters to 29.92 inches of mercury. (d) Using air data test set and altitude reporting code list (Fig. 501). Apply a static pressure to obtain test altitudes between 0 and 35,000 feet to verify the following:
NOTE:____ For each altitude selected, set corresponding code on 476X-3 test set. Observe test set mode C CODE flag appears each time mode C flag appears.
1) 2) 3) Binary code lines (A1 thru C4 and D4) between transponder and altitude source are not open or shorted to ground.Appropriate altimeter is within tolerance (AMM 34-12-00).At each altitude, the difference between test set and altimeter does not exceed | 125 feet.
EFFECTIVITY AF ALI ALL; DLH ALL; IBE ALL;
AF SAB ALL; AF, AT,MD, GN, AF AND VM WITHOUT AEB 34-587 CONFIG 1 AF AND 34-607 02 A Page 503
Oct 25/96
34-53-00
NOTE: A test altitude above 30,800 feet is required for
____ check of D4 pulse.
The altimeter reading may be increased or decreased to see if 125 ft. tolerance can be met PROVIDED the test set continues to display the designated altitude.
(e) Repeat step (d) decreasing altitude to field elevation.
(7)
Repeat altitude reporting test if ATC system has ALT source 1 - 2 selection.
(8)
Set ATC/function selector to STBY/OFF as appropriate.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航4(68)
