Cleaning Interior Surfaces - Keysight NFA Series Performance Verification And Calibration Manual

Figure E-4
NOTE

Cleaning Interior Surfaces

Interior surfaces, especially on precision 3.5mm connectors, are very
difficult to reach, and it is easy to damage connectors in trying to clean
them. The openings are very small, and generally the center conductor is
supported only at the inner end, by a plastic dielectric support bead. This
makes it very easy to bend or break the center conductor.
One suitable method (Figure E-4) is to cut off the sharp tip of a round
wooden toothpick, or a smaller diameter wooden rod, and then to wrap it
with a single layer of lint-free cleaning cloth.
Cleaning interior surfaces
Metal must never be used (it will scratch the plated surfaces), and in
cleaning precision 3.5mm connectors the diameter must not exceed 0.070
in. (1.7 mm). The wooden handle of a cotton swab, for example, is too
large for this purpose. Even though the handle can sometimes be
inserted into the connector, even when wrapped in lint-free cloth,
movement of the handle against the center conductor can exert enough
force on the center conductor to damage it severely.
Appendix E
Caring for Connectors
Cleaning
163