E8257D/67D, E8663D PSG Signal Generators Service Guide 321Assembly ReplacementA24 67 GHz Highband Coupler (Options 550 and 567)A24 67 GHz Highband Coupler (Options 550 and 567)Tools Required— T–10 driver— 5/16” open–ended wrenchRemoval ProcedureRefer to Figure 3-38 and Figure 3-39 for this procedure.1. Disconnect the power cord.2. Remove the covers from the signal generator. Refer to “Outer InstrumentCover” on page 258 and “Inner Instrument Cover” on page 260.3. Position the signal generator with the A31 Motherboard facing away fromyou and the RF deck on top.4. Using the 5/16” open–ended wrench, disconnect the A25 67 GHzHighband Detector from theA24 67 GHz Highband Coupler.5. Using the 5/16” open–ended wrench, disconnect the following cablesaccording to the signal generator you have.Standard: Disconnect W112 and W89 RF cables from the A24 67 GHzHighband Coupler’s input and output.Option 1EM: Disconnect W112 and W81 RF cables from the A24 67 GHzHighband Coupler’s input and output.Option 1EM without Option 1E1: Disconnect W112 and W91 (not shown)RF cables from the A24 67 GHz Highband Coupler’s input and output.6. Using the T–10 driver, remove the two screws that connect the A25BHighband Detector Bias Board to the A24 67 GHz Highband Coupler.7. Using the T–10 driver, remove the two screws that attach the coupler tothe side panel.8. Remove the A24 67 GHz Highband Coupler.Replacement Procedure1. Reverse the order of the removal procedure.2. Torque all T–10 screws to 9 in–lbs.3. Torque all RF connectors to 8 in–lbs.4. Perform the post–repair adjustments and performance tests that pertainto this removal procedure.
