Boonton PIM 21 User Manual - Manual (Page 17)

17 Boonton
PIM Testing
Procedures
Accurate PIM testing relies on careful methodical processes and quality testing components.
Also, the operator must be aware of the sensitivities relating to carrier power and the expected
result. See Measurement Theory section for more detail.
Components
Choosing only PIM specified components for use in any test configuration is essential. The
most common source of PIM problems are connectors and how they interface to the cable.
The following connector/cable properties are a good starting point for accurate measurements.
Connector plating
Silver plating guarantees good results.
A close second to silver is a trimetal alloy known as white copper but also goes by a
number of trade names.
Never use Nickel plated or under plated connectors.
Connector Type
7/16 DIN, a reliable low PIM connector.
N, OK for low connection cycles must check regularly.
Low PIM Adaptors.
Avoid BNC, UHF, FME.
Cable Type
Solid outer corrugated, etc.
Solder soaked conformable.
Low PIM such as RG214 and RG223 with appropriate connectors.
Do NOT use foil types such as LMR400.
Other components will include Low PIM cable loads, but never use standard lumped attenua-
tors type loads for low PIM testing.
Procedures
Always keep connector ends clean and damage free. Dropping a connector face down onto a
hard surface can nick the contact faces and degrade PIM performance.
Try to keep components used for PIM testing separate from general use components, this will
help to prolong their useful life.
Where possible tighten the connectors with a torque wrench.
During testing apply percussion and movement to cable assembles to ensure stability, vary the
severity to suit the intended application.