HP 70908A, Руководство по обслуживанию

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A1 Leveling Amplier
CA UTION
This module contains components that can be damaged or destroyed by
electrostatic discharge . It should be serviced at a static-safe workstation.
(Refer to \Preparing a Static-Safe W ork Station " in Chapter 4.)
T o Remove the A1 Leveling Amplier
1. Remove the module cover . (Refer to the \Module Cover " procedure .)
2. Remove the three screws (1) holding the A10 power supply/driver in place and fold it down.
3. Remove the one screw (2) that holds the rear-panel to the module center casting.
4. Remove the three screws (3) that hold the rear-panel to the module base .
5. Disconnect the 2 dB attenuator (4), the 3 dB attenuator (5), and W19 (6) from the
A1 leveling amplier (7). Do not damage the attenuators , the cables , or any pins on the
A1 leveling amplier .
6. Disconnect W17 (8) from the A13 ALC/bias (9).
7. Remove the four screws (10) that connect the A1 leveling amplier to the center casting.
8. Disconnect the connector (11) between the A1 leveling amplier and the A2 LO multiplier ,
and lift out the A1 leveling amplier .
T o Replace the A1 Leveling Amplier
1. P osition the A1 leveling amplier (7) on the center casting, and loosely reconnect the
connector (11) between the A1 leveling amplier and the A2 LO multiplier .
2. Loosely replace the four screws (10) that hold the A1 leveling amplier to the center
casting; these screws will be tightened in step 4.
3. Finish tightening the connector (11) between A1 leveling amplier and A2 LO multiplier .
4. Tighten the four screws (10) that hold the A1 leveling amplier to the center casting.
5. Reconnect the 2 dB attenuator (4), the 3 dB attenuator (5), and W19 (6) to the
A1 leveling amplier (7). Do not damage the attenuators , the cables , or any pins on the
A1 leveling amplier .
6. Reconnect W17 (8) to the A13 ALC/bias.
7. Replace the three screws (3) that hold the rear-panel to the module base . T orque the three
base screws to 20 inch-pounds .
8. Replace one screw (2) that holds the rear-panel to the module center casting. T orque the
one center casting screw to 6 inch-pounds .
9. F old up the A10 power supply/driver and replace the three screws (1) that hold it in place .
T orque the screws to 20 inch-pounds .
10. Replace the module cover . (Refer to the \Module Cover" procedure .)
9-12 Replacing Major Assemblies