What does a PIM test involve and what is a typical limit?

PIM (passive intermodulation) is measured by sending two high-power carrier tones into the line and listening for the products they create in the receive band. A typical analyzer setup uses 2 x 20 W (+43 dBm per tone), per the IEC 62037 method. How to run it: 1. Coordinate with the NOC so the sector is off air and nobody can transmit into your test. Keep people out of the antenna front zone: follow the site RF safety plan. 2. Calibrate with the low-PIM load; check the test jumper and adapters are clean and low-PIM rated. 3. Test the full run to the antenna, then repeat while tapping or flexing connectors, jumpers and hardware (a dynamic test). Intermittent hits matter. 4. Record the value, the test frequencies and the power in your closeout. Limits depend on the carrier. Many ask for better than about -150 dBc (roughly -107 dBm at +43 dBm tones), some tighter. Use the number in your scope. If you fail: clean, re-torque, replace jumpers, then look at loose hardware and rusty bolts near the antenna. — CrewRating Team. General guidance, not a substitute for your company safety program, manufacturer instructions or the carrier’s scope of work. If this conflicts with them, follow them and tell us so we can fix it.