LRS Micro-g LaCoste FG5, Manual, Page: 101 / 149

Troubleshooting
5
5.2.5.ELECTRONICS
The system electronics consists of the timing system, controllers for
primary subsystems, and power supplies for most components in the FG5. Some
of the electronic subsystems are manufactured by Micro-g Solutions, while
others are “off-the-shelf” components from other commercial vendors.
Electronics problems can range from catastrophic system failures to subtle,
intermittent problems which are extremely difficult to detect and diagnose.
Table 5-5 gives a list of possible electronic problems and solutions. As with the
system controller, the majority of problems encountered with this system have
been poor or missing connections during setup.
Table 5-5
Electronics Problems and Solutions
Problem Solution
A systematic gravity shift is observed The rubidium clock has lost its
calibration. Check its frequency
against a standard Cesium
reference.
Beam verticality is off
Beam is not collimated
High rotation/translation of test
mass
Wrong laser lock or the laser
hopped a peak.
Sinusoidally varying gravity value Rubidium standard is warming up
or will not lock. VCXO trim may
need adjustment.
Large noise (often looks like a
Superspring problem) Poor system grounding.
Sometimes it is necessary to
ground the system electronics rack
to an earth ground (like a water
pipe) in the laboratory.
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