Test Your System with Defined Loads

If possible, connect several well-defined, stable loads at the Autotuner output flange and test the system with them. If the signal is not CW, set the sampling mode (Waveform) and sampling parameters appropriately to get stable results (see topic Signal Waveforms and Sampling and related topics).

Recording Results

In all measurements suggested below, you may employ data logging as described in Do Data Logging, or just save the results using the File|SaveResults menu item, the SaveBin button, or the Ctrl+S shortcut key.

Matched Load

  • Connect a matched load (waterload).

  • Switch autotuning OFF and retract the tuning stubs.

  • Start measurement, observe and note the results. The measured reflection coefficient should be close to zero (depending on the waterload quality, the reflection coefficient magnitude should not exceed 0.05 to 0.1).

  • Switch autotuning ON and watch the stubs move to positions to improve the match below the set Tolerance (settable in the Autotune page of the System Info window).

Flat Short

  • Connect a flat short (a shorting plate).

  • Switch autotuning OFF.

  • Open the full-size Results Window and check Show Load.

  • Start measurement, observe and note the results. The measured load reflection coefficient magnitude should be close to unity (typically 1 ± 0.05) and the phase should be close to 180° (within a few degrees).

  • Do not attempt to start autotuning with such high-reflection loads.

Mismatch

  • If possible, set up a stable mismatched load with the reflection coefficient magnitude of about 0.5. For example, it can be a waterload preceded by a manual tuner.

  • Switch autotuning OFF.

  • Start measurement, observe and note the results.

Switch autotuning ON and watch the stubs move to positions to improve the match below the set Tolerance.