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SWITCH POSITION
POWER ON *1
RS232-RS485 RS232
*1- This switch is usually kept ON because the RS232-RS485
selector operates on the 400-Hz AC power that is supplied to
the UUT.
VMU Tuner
SWITCH POSITION
POWER OFF
ADJUST-NORMAL NORMAL
EXT-INT INT
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Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
(2) Energization of Test Equipment
(a) Set the power switches of the units shown below to ON:
· Video pattern generator
· Impedance converter
· Personal computer (PC)
· Spectrum analyzer
· VMU tuner
· Video monitor
· Oscilloscope
(b) Set the tester's POWER switch to ON. You will hear the fan
sound and 400-Hz hum from the UUT.
NOTE: The tester's POWER switch controls the 400-Hz AC power to
the UUT and to the RS232-RS485 selector of the test
harness.
(c) Give the units a warm-up time of 2 hours or more, during which
do the adjustments and setting given in (3), (4) and (5). You
can also do the initial part of the functional testing before
the warm-up time comes.
NOTE: A warm-up time of 2 hours or more is necessary for the UUT
to measure its RF output levels. A warm-up time of 30
minutes or more is necessary for some of the instruments
such as the spectrum analyzer.
(3) Video Input Adjustments
(a) Set the video pattern generator for a white-raster output.
(b) Get a video signal waveform as shown in Figure 112 with the
oscilloscope set as follows:
ITEM SETTING
CH1 Coupling AC.
CH1 Sensitivity 0.2 V/division.
Sweep Time 10 ms/division.
Trigger Source CH1.
Trigger Coupling DC or TV line (TV horizontal)
Trigger Slope Negative (-)
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Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
IF YOU USE THE IMPEDANCE CONVERTER OR IF THE VIDEO PATTERN GENERATOR GIVES
AN OUTPUT WITH AC COUPLING, YOU WILL SEE BLURS ON THE WAVEFORM AS SHOWN
BELOW.
(100 IRE)
(40 IRE)
(140 IRE)
1 Vp-p
0.71 Vp-p
0.29 Vp-p
BLUR
BLUR
BLUR
MEASURE THE
AMPLITUDE
BETWEEN THE
BOTTOM LINES
OF BLURS.
WAVEFORM
WAVEFORM
WITH DC
COMPONENT
CORRECT
REMOVED
BLUR
H SYNC
100% WHITE
SYNC PULSE
IF YOU SEE THE BLURS ON THE WAVEFORM, MEASURE THE AMPLITUDE BETWEEN THE
BOTTOM SIDES OF THE TOP AND BOTTOM BLURS.
GENERAL INSTRUCTIONS TO MEASURE
THE AMPLITUDE OF BASEBAND VIDEO SIGNAL
Figure 112
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Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
(c) Adjust the video signal output of the video pattern generator
accurately to 1.0 Vp-p in amplitude as measured on the
oscilloscope.
(d) Set the CH1 sensitivity of the oscilloscope to 0.5 V/division,
and make sure that the amplitude of the video signal is 1 Vp-p.
(e) Disconnect the BNC tee adapter T1 from the VIDEO INPUT CH1
connector of the tester with the VC3 and VC4 cables as
connected.
(f) Make sure that the amplitude of the video signal is increased to
2 Vp-p.
(g) Connect the BNC tee adapter T1 to the VIDEO INPUT CH1 connector
of the tester.
(h) Set the CH1 sensitivity of the oscilloscope to 0.2 V/division.
(4) Spectrum Analyzer Setting
Set the spectrum analyzer for RF carrier measurements of 130 thru
330 MHz in frequency and the level as given below:
UUT RF CARRIER LEVEL
RD-AA5002-12 without MOD2 108 dBmV (±3 dB)
RD-AA5002-12 with MOD2 102 dBmV (+3/-4 dB)
RD-AA5002-22 without MOD4 108 dBmV (±3 dB)
RD-AA5002-22 with MOD4 102 dBmV (+3/-4 dB)
RD-AA5002-23 without MOD3 108 dBmV (±3 dB)
RD-AA5002-23 with MOD3 102 dBmV (+3/-4 dB)
RD-AA5002-25 102 dBmV (+3/-4 dB)
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Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
(5) VMU Tuner Setting
(a) Make sure that the VMU tuner shows as follows:
DISPLAY DATA
CH 01
FREQ 151.25 or different frequency value
NOTE: If the VMU tuner shows "E0" or "E2" on the CH display, the
VMU tuner must be repaired before you can use it.
(b) Do a scan of channels 1 thru 12 with the UP or DOWN switch
pushed and make sure that the default receiving frequencies are
set on these channels (refer to Figure 1004). If not, set the
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(65)
