Fast Frequency Measurement

Sometimes, it is useful to examine the time dependence of a magnetron’s instantaneous frequency. This is the case, for example, with high-ripple signals pulsing at power-line-related ripple frequency. To make such measurement, proceed as follows:

• Select the Freq display.

• Close both Result Windows. Updating the windows is time-consuming, and thus decreases thus the measurement cadence. For the same reason, you may wish to close all graphical displays except the Freq window.

• Set the Homer for fast frequency measurement by choosing a small frequency count time, e.g., 100 ms or less. To do this, click the Homer|Count Time menu or the  Tc  button. Later, you can experiment with this setting.

• Select CW sampling mode.

• Set a sufficient number of measurement points (via the Homer|Points per Sweep menu, the Ctrl+N shortcut, or the  Pts  button).

• Activate the button, thus disabling all measurements except the frequency measurement.

• Start measurement.

After completing the measurement, you may wish to save the results. Please note that:

• The x-axis is the measurement count and does not represent exact time.

• The only relevant data column in the file is the frequency (f_MHz).