Removing And Replacing The A38-A41 Bias Tees - Keysight N5221A Service Manual

Repair and Replacement Procedures
Removing and Replacing the A38–A41 Bias Tees
Removing and Replacing the A38–A41 Bias Tees
Tools Required
• T-10 TORX driver (torque to 9 in-lb or 1.02 N.m)
• T-20 TORX driver (torque to 21 in-lb or 2.38 N.m)
• 5/16-inch open-end torque wrench (torque to 10 in-lb or 1.13 N.m)
• ESD grounding wrist strap
Removal Procedure
Refer to Figure 7-21 for this procedure.
CAUTION Be careful not to damage the center pins of the semirigid cables. Some flexing of the cables
is necessary to remove assemblies but do not over-bend them.
1. Disconnect the power cord.
2. Remove the outer cover. Refer to
3. Remove the front panel assembly. Refer to
page 7-8.
4. Position the analyzer bottom side up.
5. On some 4-port models, it may be necessary to remove the attenuator bracket to which the bias tee is
attached to facilitate replacing the bias tee. If this is the case, refer to
A34–A37 Source Attenuators, the A38–A41 Bias Tees, and the A42–A45 Receiver Attenuators" on page
7-42.
6. Disconnect two semirigid cables (item
7. Remove two screws (item
harness cable ground wire for reinstallation later.
8. Disconnect the wire harness cable (item
9. Move the disconnected semirigid cables out of the way and remove the bias tee from the analyzer. Do
not overbend them.
Replacement Procedure
1. Reverse the order of the removal procedure.
Torque all cable connections to 10 in-lbs.
Remember to place the wire harness cable ground lug on the proper mounting screw.
2. As shown in Figure 7-22, position the bias tees on the attenuator brackets so that the port 1 and port 3
bias tees capacitors face each other. The port 2 and port 4 bias tee capacitors should also face each
other.
3. Perform the post-repair adjustments, verifications, and performance tests that pertain to this removal
procedure. Refer to Table 7-2 on page
7-44
"Removing the Covers" on page
"Removing and Replacing the Front Panel Assembly" on
①
) from the bias tee to be removed.
➁
) from the bias tee to be removed. Make note of the location of the wire
③
) from the bias tee.
7-56.
PNA Series Microwave Network Analyzers
7-6.
"Removing and Replacing the
Service Guide N5222-90001
N5221A/22A