Plain-language answer: Reciprocal mixing is noise created when a receiver’s local-oscillator phase noise mixes with a strong nearby signal and raises the apparent noise around the tuned frequency.
Why the definition matters
It can hide weak stations even when filters and classical intermodulation performance are otherwise good. Closer and stronger adjacent signals make the problem more visible.
Use the number correctly
Use narrow appropriate bandwidth, reduce unnecessary gain, compare receiver reciprocal-mixing specifications, and improve antenna or external filtering when practical.
The common mistake
Calling the raised noise floor propagation noise without testing the effect of the nearby strong signal.
Measurement and safety boundary
Keep reference units, bandwidth, detector, direction, averaging, and test conditions attached to every number. Current regulator requirements and the complete installed system control RF-exposure compliance.
