Installation guide

Assembly Replacement
AT1 High-Power Mechanical Attenuator (Option UNB) with A28 Reverse Power Protection (Option 501, 502, 503, 504 or
Option UNJ)
2-63
AT1 High-Power Mechanical Attenuator (Option UNB) with
A28 Reverse Power Protection (Option 501, 502, 503, 504 or
Option UNJ)
Tools Required
• T-10 driver
• 5/16” open ended wrench
Removal Procedure
Refer to Figure 2-32 for this procedure.
1. Disconnect the power cord.
2. Remove the outer and top inner cover. Refer to “Outer and Inner Instrument Covers” on page 2-4.
3. Using the 5/16” open ended wrench:
• disconnect W47 and W48
• disconnect W49
On signal generators with Option 1EM, disconnect W86. (Refer to “Option 501, 502, 503, 504 - Option
1EM Semi-Rigid Cables includes the AT1 Electronic Attenuator (Option 501, 502, 503, 504 or
Option UNJ) or the AT1 High-Power Mechanical Attenuator (Option UNB) with the A28 Reverse
Power Protection (Option 501, 502, 503, 504 or Option UNJ)” on page 3-35.)
4. Disconnect W57 from A23J25.
5. Disconnect W53 from A23J22.
6. Using the T-10 driver, remove the two screws (1) from the AT1 bracket that secures
the AT1 High-Power Mechanical Attenuator (Option UNB) and the A28 Reverse Power Protection
(Option 501, 502, 503, 504 or Option UNJ) to the chassis.
7. Tilt the AT1 bracket away from the chassis and slide out the tabs from the slots.
There are two hinged tabs at the bottom of the AT1 bracket that fit into slots in the signal generator’s
chassis.
8. Using the T-10 driver remove the four screws (2) that attach the RPP bracket
to the AT1 bracket.
9. Using the T-10 driver remove the four screws (3) that attach the AT1 High-Power Mechanical Attenuator
(Option UNB) to the AT1 bracket.
10.Using the T-10 driver remove the three screws (4) that attach the A28 Reverse Power Protection
(Option 501, 502, 503, 504 or Option UNJ) to the RPP bracket.
11.Remove the A28 Reverse Power Protection (Option 501, 502, 503, 504 or Option UNJ).