E8257D/67D, E8663D PSG Signal Generators Service Guide
Assembly Replacement
A28 YIG Oscillator
3-78
A28 YIG Oscillator
Tools Required
• T–10 driver
• 5/16” open–ended wrench
Removal Procedure
Refer to Figure 3- 49 for this procedure.
1. Disconnect the power cord.
2. Remove the covers from the signal generator. Refer to “Outer Instrument Cover” on page 3- 4 and “Inner
Instrument Cover” on page 3- 6.
3. Position the signal generator with the A31 Motherboard facing you and the RF deck on top.
4. Using the 5/16” open–ended wrench, disconnect the following RF cable according to the signal generator you have:
E8257D & E8663D: Disconnect the W41 RF cable from the A28J1.
E8267D: Disconnect the W101 RMF cable from the A28J1.
5. Disconnect the W12 ribbon cable from the A28 YIG Oscillator’s driver board.
6. Using the T–10 driver, remove the two screws (1) that attach the A28 YIG Oscillator to the side panel.
7. Using the 5/16” open–ended wrench, disconnect the W27 RF cable from the A30 Modulation Filter with High
Power.
8. Remove the A28 YIG Oscillator.
Replacement Procedure
1. 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 pertain to this removal procedure.