PPI-1N INDICATOR 1
TDA PULSE OFF (BLACK)
RNG 180 MRK 30
GREEN
TDA PULSE ON (GREEN)
RED
GREEN STC
GREEN YELLOW (BLACK) YELLOW
PPI-1T 2
1 AT ALL; AZ 231-280; LH ALL; IB 406-499
2 AZ 225-229,281-299
Self-Test Display Pattern Figure 101 (Sheet 3)
EFFECTIVITYAT ALL; LH ALL; CONFIG 1 AZ 225-299; IB 406-499799 Page 107
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...XA
WARNING: THIS TEST IS ACCOMPLISHED WITH THE "TEST" (NON-RADIATING) MODE SELECTED ON THE WEATHER RADAR CONTROL PANEL. DO NOT SELECT OTHER OPERATING MODES UNLESS "XMTR" SWITCH IS SET TO "OFF" POSITION ON R/T, OR ALL OTHER CON-DITIONS ARE SAFE FOR TRANSMITTING FROM THE RADAR ANTENNA. REFER TO PRECAUTIONS IN PAR. 2.
Prepare system for troubleshooting as described in par. 2. Press control panel TEST pushbutton. Adjust BRIGHTNESS control on both indicators for desired level. IF -
AF 157,161; AZ 201-224; Set RANGE to max range indicated on Fig. 101, vary offset control on each indicator from AHEAD, to LT, to RT and back to AHEAD. Check that the apex of the display shifts to the right for LT offset and to the left for RT offset. IF -
EFFECTIVITYAF 157,161; AT ALL; AZ ALL;
CONFIG 1 IB 406-499; LH ALL7XA Page 108
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OK
... .. .......XA
Vary the RANGE setting on each indicator and verify that the range marks configuration displayed is as follows:
_____ _____________________RANGE MARKS LOCATIONS
RANGE
AZ 201-224 50 25,50 (PPI-IL) 150 50,100,150 30050,100,150,200,250,300
AF 157,161
(PPI-1L 50 20,40
100 20,40,60,80,100
200 50,100,150,200
AT ALL (PPI-IN) 25 25
50 25,50 150 50,100,150 300 50,100,150,200,250,300
IB 406 THRU 499 (PPI-IN); 30 10,20,30 8025,50,75 18025,50,75,100,125,150,175
AZ 231-280 (PPI-IN); 300 50,100,150,200,250,300LH ALL (PPI-IN)
AZ 225-229,281-299 30 10,20,30
(PPI-IT) 8020,40,60,80
18030,60,90,120,150,180
300 50,100,150,200,250,300
IF -
EFFECTIVITY AF 157,161; AT ALL; AZ ALL;
CONFIG 1 IB 406-499; LH ALL7XA Page 109
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NOT OK
NOT OK
OK
NOT OK
NOT OK
TEST PATTERN OK ON BOTH INDICATORS BUT PERIODICALLY BREAKS UP - Reset VSWR fault lamps on R/T's, then select TEST mode at control panel. If VSWR fault lamp(s) come on, fault most probable in waveguide switch, waveguide between switch and R/T's, or dummy load. If VSWR fault lights remain out in TEST mode and conditions are safe for transmitting from antenna, select NORM or other radi-ating mode and check VSWR fault lamp(s) again. If on,
trouble probably in antenna or waveguide from antenna to waveguide switch. Check and replace defective components as required. Worn waveguide rotary joints in antenna (especially at maximum tilt angles) and water in wave-guide can cause VSWR and RF output power depletion. Check units, replace faulty units, and perform specified test (AMM 34-43-03/401 and AMM 34-43-04/401).
Vary BRIGHTNESS (BRT) control on each indicator and check that video intensity changes. IF -
AT All; Check that the operation of SCAN/HOLD control is correct (Ref. Adjustment/Test procedures). IF -
T35110
EFFECTIVITY AF 157,161; AT ALL; AZ ALL;
CONFIG 1 IB 406-499; LH ALL799 Page 110
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..XA
Check flight log for a report of antenna tilt problems. IF -
System is OK.
EFFECTIVITYAF 157,161; AT ALL; AZ ALL;
CONFIG 1 IB 406-499; LH ALL7XA Page 111
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PROCEDURE 1
PROCEDURE 2
PROCEDURE 3
T35125
EFFECTIVITYAF 157,161; AT ALL; AZ ALL;
CONFIG 1IB 406-499; LH ALL 799 Page 112
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WEATHER RADAR SYSTEM - TROUBLE SHOOTING
_______________________________________
1. General
_______
A. The following trouble shooting procedures are based on performance of the system operational test and are presented in tree-type format. The test steps (heavy-line boxes) are connected by shaded arrows to show the OK condition path. When all steps in the OK condition path check out, the system is operable.
B. When a test step does not check out, follow the NOT OK line to the box containing the trouble symptom. Turn to the procedure indicated and continue to follow a single line by analyzing the results of each test step until the required corrective action is determined. Perform the specified corrective action; then repeat the step at which the failure was encountered.
C. The self-test features incorporated in the system provide a quick means of evaluating system performance. When the TEST mode is selected at the control panel function selector, a special test pattern is generated for evaluation of a large portion of the system. In addition the system incorporates fault isolation circuitry which provides visual indication, on the receiver-transmitter units front panel, of an existent malfunction within the system. By utilization of the internally generated test pattern together with the outputs of the system fault indicators and annunciators, the system is capable of detecting most system malfunctions.
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