7-42 Service Guide N5242-90001
Repair and Replacement Procedures PNA Series Microwave Network Analyzers
Removing and Replacing the A34–A37 Source Attenuators, the A38–A41 Bias Tees, and the A42–A45 Receiver Attenuators
N5242A
Removing and Replacing the A34–A37 Source Attenuators,
the A38–A41 Bias Tees, and the A42–A45 Receiver Attenuators
Tools Required
• T-10 TORX driver (set to 9 in-lb)
• T-20 TORX driver (set to 21 in-lb)
• 5/16-inch open-end torque wrench (set to 10 in-lb)
• ESD grounding wrist strap
Removal Procedure
Refer to Figure 7-20 for this procedure.
CAUTION
Be careful not to damage the center pins of the semirigid cables. Some flexing
of the cables is necessary, but do not over-bend the semirigid cables.
1. Disconnect the power cord.
2. Remove the outer cover. Refer to “Removing the Covers” on page 7-6.
3. Remove the front panel assembly. Refer to “Removing and Replacing the Front Panel
Assembly” on page 7-8.
4. Position the analyzer bottom side up.
5. The source and receiver attenuator pair, the associated bias tee, and the bracket to
which they are attached, must be removed as a complete assembly.
6. Disconnect the ribbon cable (item
①
) from the attenuators to be removed.
7. Disconnect the wire harness cable (item
②
), for the bias tee to be removed, from the
A19 test set motherboard.
8. Disconnect two semirigid cables (item
③
) from each step attenuator and the bias tee to
be removed. It may be necessary to remove additional cables to remove the attenuator
bracket. If so, note the location and orientation of each for reinstallation later.
9. Remove three screws (item
④
) that secure the attenuator bracket to the test set deck.
10. Move the disconnected semirigid cables out of the way and lift the attenuator bracket
out of the analyzer, with the attenuators and bias tee attached.
11. Remove two screws (item
⑤
) to remove the attenuator or bias tee to be replaced, from
the mounting bracket.
Replacement Procedure
1. Reverse the order of the removal procedure.
Torque all cable connections to 10 in-lbs.
2. Perform the post-repair adjustments, verifications, and performance tests that pertain
to this removal procedure. Refer to Table 7-2 on page 7-64.
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