LO Output Power Accuracy Option EXM Performance Test

This test applies to the following models with Option EXM:

LO Output Power Accuracy test can no longer be run outside of 20–30 °C.


This test verifies that X-Series Spectrum Analyzers equipped with External Mixing (Option EXM) meet their specification for LO output level. The 11970 Series mixers require LO drive levels in the +14.0 to +18.0 dBm range.

In this test the signal analyzer is placed in external mixing mode using a harmonic number of –1, or +1. The signal analyzer center-frequency is tuned from 4.0 to 8.4 (Doubler off) or 8.1 to 13.8 GHz (Doubler on). A power sensor is connected to the External Mixer port on the signal analyzer and the LO power is measured.

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Required Test Equipment

Test Equipment

Recommended Model Number

Power meter


Power sensor


3.5 mm (f) to Type-N (m)
(8485A adapter)


Adapter, 3.5 mm (m) to 3.5 mm (f)


Connection Setups

Power Meter Calibration (Channel A)


LO Output Power Accuracy Test Setup

Occasionally, due to manufacturing tolerances, the front panel may prevent the power sensor from fully seating on the External LO Connector. If this situation occurs, a 3.5 mm (m) to 3.5 mm (f) adapter (such as the 83059C) should be used to position the power sensor further from the front panel.