Post Regulator Board Replacement; A27 Post Regulator Board Assembly - HP 8517B Operating & Service Manual

Post Regulator Board
Replacement
NOTE
NOTE

A27 Post Regulator Board Assembly

This procedure is for Option 007, Option 002 "plus" 007, and Option 004
"plus" 007, only.
1. See the figure in Chapter 7, Table 7-17 for the location of the A22
amplifier bracket. The A27 board assembly is located beneath the A22
amplifier bracket.
2. Without removing the step attenuator from the bracket (this step is not
applicable to Option 002 "plus" 007), remove the four semi-rigid cables
attached to the attenuators at Port 1 and Port 2.
3. Remove the four buffer amplifiers from the bracket (refer to "A23 to
A26 Buffer Amplifiers").
4. Remove the A18 switch/splitter assembly (refer to "A18 Switch/Splitter
Assembly").
5. Remove the A22 input amplifier (refer to "A22 Input Amplifier
Assembly").
6. Remove the four screws attaching the amplifier bracket to the test set.
7. Flip the amplifier bracket over. Note the A27 board assembly mounted
to the underside of the bracket.
8. De-solder the two pins from the regulator to remove the A27 amplifier
regulator board assembly.
9. Remove the five screws holding the board assembly to the bracket.
10. Remove the two screws holding the voltage regulator to the bracket.
11. Remove the regulator board assembly from the amplifier mount bracket.
Do not loosen the grommets (HP part number 3050-0003) located on the
regulator board assembly.
12. For reassembly, install two grommets on the underside of the mount
bracket. There are two cut-outs on the sheet metal for these grommet
insulators.
HP 8517B Test Set Replacement Procedures
Assembly Replacement Procedures
HP 8517B S-Parameter Test Set Manual 6-13