Start here: An SWR meter estimates the standing-wave ratio on a feed line from sampled forward and reflected waves.
Why it matters
Accuracy depends on directivity, calibration, power, frequency, connector quality, and line conditions. It reports mismatch at its reference point, not antenna efficiency.
A practical example
A low reading at the radio can coexist with high line loss that hides a severe load mismatch.
Use it well
Use the meter in its rated range, check into a known load, and measure closer to the antenna when diagnosing the system.
Operating boundary
Keep the measurement reference plane, current program rules, land access, spectrum authorization, and exact packed configuration with the decision. A connector, meter reading, or program name alone does not establish readiness.
