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7. Adjustments
Do the adjustment procedures given below as necessary and as continued from
the functional testing. You can do each adjustment procedure independently.
A. Disassembly Necessary for Adjustments
(1) Do not set the tester's POWER switch to OFF if you adjust the RF
levels.
(2) Disassemble as follows:
ADJUSTMENT DISASSEMBLY
RF levels and/or
modulation depth
Remove the top cover assembly [1-10].
Output level of internal
video signal generator
Put the UUT with its top down, then remove the
bottom cover [1-35].
B. RF Levels
If it is necessary to adjust the RF level of a modulator channel, we
recommend that you adjust the RF levels of all modulator channels as
given below.
(1) Use the same setup as the functional test setup (Figure 103).
(2) RF Output Connections
(a) Connect the RF OUTPUT RF1 connector of the tester to the input
of the spectrum analyzer with an RF cable (RFC1).
(b) Connect BNC 50-W terminators to the RF OUTPUT RF2, RF3 and RF4
connectors of the tester.
(3) Disconnect the BNC tee adapter T1 from the tester (no modulation).
(4) Make sure that the UUT is energized for more than 2 hours.
(5) Make sure that the spectrum analyzer shows 12 picture carriers from
151.25 to 283.25 MHz.
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
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(6) Turn the variable resistor A2VR202 on each A2 card to set the level
of each picture carrier to:
UUT RF CARRIER LEVEL
RD-AA5002-12 without MOD2,
RD-AA5002-22 without MOD4,
RD-AA5002-23 without MOD3
108 dBmV ±0.5 dB
RD-AA5002-12 with MOD2,
RD-AA5002-22 with MOD4,
RD-AA5002-23 with MOD3,
RD-AA5002-25
102 dBmV ±0.5 dB
Refer to Figure 103H for the location of the variable resistor
A2VR202.
VR202 VR201
RF VIDEO
FRONT
REAR
LOCATION OF VARIABLE RESISTORS ON A2 CARD
Figure 103H
(7) RF Output Connection Change for RF2 Measurements
(a) Disconnect the BNC 50-W terminator from the tester's RF OUTPUT
RF2 connector.
(b) Disconnect the RFC1 cable from the tester's RF OUTPUT RF1
connector, and connect it to the RF OUTPUT RF2 connector.
(c) Connect the BNC 50-W terminator to the tester's RF OUTPUT RF1
connector.
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
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(8) Make sure that the level of each picture carrier is:
UUT RF CARRIER LEVEL
RD-AA5002-12 without MOD2,
RD-AA5002-22 without MOD4,
RD-AA5002-23 without MOD3
108 dBmV ±1.0 dB
RD-AA5002-12 with MOD2,
RD-AA5002-22 with MOD4,
RD-AA5002-23 with MOD3,
RD-AA5002-25
102 dBmV ±1.0 dB
(9) RF Output Connection Change for RF3 Measurements
(a) Disconnect the BNC 50-W terminator from the tester's RF OUTPUT
RF3 connector.
(b) Disconnect the RFC1 cable from the tester's RF OUTPUT RF2
connector, and connect it to the RF OUTPUT RF3 connector.
(c) Connect the BNC 50-W terminator to the tester's RF OUTPUT RF2
connector.
(10) Make sure that the level of each picture carrier is:
UUT RF CARRIER LEVEL
RD-AA5002-12 without MOD2,
RD-AA5002-22 without MOD4,
RD-AA5002-23 without MOD3
108 dBmV ±1.0 dB
RD-AA5002-12 with MOD2,
RD-AA5002-22 with MOD4,
RD-AA5002-23 with MOD3,
RD-AA5002-25
102 dBmV ±1.0 dB
(11) RF Output Connection Change for RF4 Measurements
(a) Disconnect the BNC 50-W terminator from the tester's RF OUTPUT
RF4 connector.
(b) Disconnect the RFC1 cable from the tester's RF OUTPUT RF3
connector, and connect it to the RF OUTPUT RF4 connector.
(c) Connect the BNC 50-W terminator to the tester's RF OUTPUT RF3
connector.
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
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(12) Make sure that the level of each picture carrier is:
UUT RF CARRIER LEVEL
RD-AA5002-12 without MOD2,
RD-AA5002-22 without MOD4,
RD-AA5002-23 without MOD3
108 dBmV ±1.0 dB
RD-AA5002-12 with MOD2,
RD-AA5002-22 with MOD4,
RD-AA5002-23 with MOD3,
RD-AA5002-25
102 dBmV ±1.0 dB
(13) Do the functional testing again.
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
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C. Modulation Depth
This paragraph gives the procedure to adjust the modulation depth of one
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(42)
