Define each output by waveform, nominal frequency, level, impedance, connector, load, edge rate or phase-noise requirement and simultaneous fan-out state. Measure at the consumer connector with the actual cable and termination. A receiver's internal timing specification does not include an unmeasured distribution amplifier, splitter or field cable.
Separate absolute path delay from relative channel skew. Calibrate or characterize antenna-cable delay, receiver processing delay and each distribution path when absolute time matters. For relative synchronization, verify channel-to-channel delay, phase or edge repeatability, load sensitivity, crosstalk and temperature drift. Store per-channel compensation with serial and revision identity.
Use a time-interval counter, phase comparator or suitable oscilloscope against a reference whose uncertainty supports the limit. Test warm-up, all active outputs, cable replacement, temperature, power cycling and reference reacquisition. Retain raw phase or time data, instrument configuration, uncertainty and alarm state so the delivered timing claim can be reconstructed.