Procedure 7.
A6Al
High Voltage Assembly
Procedure 7.A6Al High Voltage Assembly
Removal
Warning
The A6 power supply and
A6Al
high voltage assemblies contain lethal voltages
with lethal currents in all areas. Use extreme care when servicing these
assemblies. Always disconnect the power cord from the instrument before
beginning this replacement procedure. Failure to follow this precaution can
represent a shock hazard which may result in personal injury.
1. Disconnect the power cord from the spectrum analyzer.
2. Remove the spectrum analyzer cover assembly as described in “Procedure 1. Spectrum
Analyzer Cover.”
3. Fold out the A2, A3, A4, and A5 assemblies as described in “Procedure 5. A2, A3, A4,
and A5 Assemblies.”
4. Place the spectrum analyzer top-side-up on the work bench.
Warning
The voltage potential at
A6AlW3
is
t9
kV.
Disconnect at the CRT with
caution1
Failure to properly discharge
A6AlW3
may result in severe
electrical shock
to
personnel and damage to the instrument.
5. Connect the spectrum analyzer line-power cord to provide proper grounding while
discharging the
A6AlW3
post-accelerator cable. Make sure that the spectrum analyzer
line-power switch is in the off position.
6. Connect a high voltage probe
(lOOO:l),
such as the HP 34111A to a voltmeter with a
10
megohm
input.
7. Connect the clip lead of the probe (ground) to the chassis of the spectrum analyzer.
8. Slip the tip of the high voltage probe under the rubber shroud of the
A6AlW3
post-accelerator cable to obtain a reading on the voltmeter. See Figure 4-2.
9. Keep the high voltage probe on the post-accelerator connector until the voltage has
dropped to a voltmeter reading of less than 5
mV
(less than 5 V at the connector). This
normally takes about 30 seconds.
10. Disconnect the line-power cord from the spectrum analyzer.
11. Using a small screwdriver with the shank in contact with the CRT shield assembly, slip
the tip of the screwdriver under the rubber shroud of the
A6AlW3
post-accelerator cable
and short the cable to ground on the CRT shield assembly. See Figure 4-2.
12. Pry out the black grommet protecting post-accelerator cable
A6AlW3
from the CRT
shield assembly.
13. Carefully unsnap the
A6AlW3
post-accelerator cable from the CRT and discharge it by
shorting the cable to chassis ground on the CRT shield assembly.
14. Remove the three screws securing the power supply shield to the power supply and remove
the shield.
Assembly Replacement 4-25