Service; Repair - Agilent Technologies 8498A Operating And Service Manual

Fixed attenuator

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CAUTION

Service

Repair of the attenuator is limited to the replacement of the attenuator

cartridge assembly (16) shown in Figure 2.

Refer to Figure 2 to identify the numbered items in the following procedure.

Attenuator Disassembly Procedure

1. Remove the 8 screws (10) that hold the two attenuator housings

(9) and (30) and remove the housings.

2. Remove the three screws (36) and lock washers (35) from both ends of

the attenuator assembly.

3. Remove the end fins (31) and (34), the RFI seals (11) and (19),

spacers (33), and the framed attenuator fins (32).

4. Remove the three cap screws (12) from both ends of the attenuator

assembly. It may be necessary to move the housing slightly to remove

the screws.

5. Slide the inner connector bodies (14) and (18) from the attenuator

cartridge assembly (16). Be careful not to let the sliding contacts (8) and

(29) and compression springs (7) and (28) slide from the contact holders

(6) and (27). Under normal conditions they will not slide out.

6. At this point the attenuator cartridge assembly (16) and the shim

washers are free from the overall assembly and can be returned to

Agilent Technologies. The attenuator cartridge assembly is the housing

for the attenuator card, the card half sections, and the shims.

Attenuator Reassembly Procedure

1. Place the framed attenuator fins (32), "D" ring spacers (33), and end fins

(31) and (34) on the attenuator cartridge assembly (16).

2. Position the RFI seals (11) and (19) and install end fins (31) and (34)

with screws (36) and lock washers (35).

3. Install the connector assemblies with the six screws (12). Use the end of

a toothpick to apply two small drops of Loctite 262 for each screw to the

threads in the attenuator body (16). Tighten the screws evenly to a torque

specification of 0.90 Nm (8 in-lbs).

Overtightening screws (12) beyond the specified torque may distort the card

clamp half sections and fracture the attenuator card.

6 Agilent Technologies 8498A Operating and Service Manual

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