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1 FREQ 2 NORM 3 AUTO 4 5NOFALT 6 BITE 7 VIDEO 8 PRINT 9 NEW 10 QUIT
MAIN SCREEN
Figure 103E
(7) The UUT is satisfactory in data communication. Do as follows:
(a) Compare the frequency values shown on the screen with the normal
set of VHF carrier frequencies given below:
CH FREQUENCY CH FREQUENCY CH FREQUENCY
1 151.25 5 199.25 9 247.25
2 163.25 6 211.25 10 259.25
3 175.25 7 223.25 11 271.25
4 187.25 8 235.25 12 283.25
(b) If the frequency values shown on the screen are different from
the normal set, record the frequencies for CH1 thru CH12 to put
them back to the UUT at the end of the testing and go to step
(c). If the frequency values shown on the screen agree with the
normal set, go to (d).
(c) Push the F2 key (NORM) and then the Enter key. The program will
set the normal set of VHF carrier frequencies on the UUT.
(d) Go to step (10).
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Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
(8) The data communication function of the UUT is defective and it is
necessary to repair the VMU. Do as follows:
(a) Set the tester's POWER switch to OFF to de-energize the UUT.
NOTE: It is not necessary to stop the program. This step gives
no unwanted effect on the program operation because there
is no data communication between the PC and the UUT.
(b) Go to "6. Fault Isolation".
(9) The UUT's one or more channels are defective. Do as follows:
(a) Monitor the screen until the frequency and time values are shown
for all channels.
NOTE: It is possible that more than ten minutes is necessary for
all values to show.
(b) Record the channel number shown "FAULTED", then push the F9 key
(NEW) and the Enter key to go back to the condition of Figure
103B. The program operation stops.
NOTE: This step is necessary to prevent an unwanted effect of
the UUT de-energization on the program operation.
(c) Set the tester's POWER switch to OFF to de-energize the UUT.
(d) Go to "6. Fault Isolation".
(10) General Instructions for Program Operation
(a) If the data communication is stopped, such as by removal of the
RS-232 null-modem cable or because the VMU is de-energized, the
program will come to a halt and you must restart the PC to let
the program operate correctly. If it is necessary to deenergize
the UUT, first stop the program with the F9 key (NEW)
and Enter key, then push the tester's POWER switch to OFF.
(b) If the program does not operate correctly (program runaway):
· Push the Esc key.
· If the Esc key has no effect, hold down the Ctrl key and push
the Pause key.
· You will see a message "Hit any key to return to system", and
push the Enter key.
· You will see the DOS prompt "A:\>", type "vmutest", then push
the Enter key to restart the program.
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Feb 20/2002
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
B. Video Level Test
(1) Make sure on the spectrum analyzer that there are 12 RF carriers
(151.25 thru 283.25 MHz). If there is no RF carrier for one
channel, do as follows:
(a) Push the F9 key (NEW) and the Enter key to stop the program
operation and to go back to the condition of Figure 103B.
(b) Set the tester's POWER switch to OFF to de-energize the UUT.
(c) Go to "6. Fault Isolation".
(2) Disconnect the RFC1 cable from the tester's RF OUTPUT RF1 connector.
(3) Connect the RFC2 cable from the VMU tuner input to the tester's RF
OUTPUT RF1 connector.
(4) Make sure on the oscilloscope that the video signal amplitude is 1.0
Vp-p, then disconnect the VC2 cable from the BNC tee adapter T1.
(5) Connect the VC2 cable to the BNC tee adapter T2 to measure the video
output of the VMU tuner.
(6) Set the VMU tuner for reception of CH1 ("01" on the CH display and
"151.25" on the FREQ display).
(7) Measure the video output level of the VMU tuner on the oscilloscope.
(8) The result is satisfactory if the video output level is:
1.0 ± 0.1 Vp-p (0.9 thru 1.1 Vp-p).
(9) Record the channel number if the result is unsatisfactory. Connect
the VC2 cable to the BNC tee adapter T1.
Page 128
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
(10) Do steps (4) thru (9) for CH2 thru CH12. For part numbers
RD-AA5002-23 and RD-AA5002-25, do as follows for the channel(s)
specified:
UUT OPERATION CHANNEL(S)
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(34)
