Additive ON (default): every enabled mechanism is orthogonal and is added independently to the baseline. Additive OFF: enabled mechanisms are also combined, so compound TX/source and RX susceptibility equations are enumerated and labelled with all contributing mechanisms. TX/RX Nyquist define the usable digital baseband limits; DAC/ADC sample rates are 2× their Nyquist values. RX.LO adds RX-LO coupling into the TX mixer; TX.LO adds TX-LO coupling into the RX mixer. DAC/ADC alias counts select the highest Nyquist zone checked; Zone 1 is the baseline, Zone 2 spans Nyquist…Fs, Zone 3 spans Fs…Fs+Nyquist, with alternating spectral inversion.

Fixed per LO + passband combination (not per spur). Baseband is passband − LO, shown with its sign. Image RF is the passband mirrored through the LO (2·LO − passband) — the classical RF image frequency for that LO placement. A row is highlighted in red when its baseband magnitude exceeds that path's Nyquist limit.

Save/Load stores the LOs, cutoff, n/m max, display options and all TX/RX passbands so a case can be reloaded later.

Additive keeps enabled optional mechanisms independent. With Additive off, compound mechanisms are generated and every contributing mechanism is shown in the Type / TX mechanism / RX mechanism fields. A hit means a calculated source RF interval overlaps a checked RX susceptibility mechanism. With every checkbox off, only the baseline single-TX mixer products and wanted/optional-image RX targets are evaluated. Each checkbox adds one separately labelled mechanism family so the source of a hit remains identifiable. Rows tinted purple are TX cross-band intermodulation terms. The table is intended as an LO-selection aid, not a spur-amplitude prediction.