3.1 Basic Settings 3.1.1 FREQ Set the frequency parameters of the analyzer. The analyzer sweeps within a specified frequency range, and the sweep is restarted every time you change the frequency parameters. The frequency range of a channel can be expressed by either of two groups of parameters: Start Frequency and Stop Frequency （ f start / f stop ） ; or Center Frequency and Span （ f center / f span ） . If any of the parameters is changed, the others would be adjusted automatically in order to ensure the coupling relationship among them: center f = ( ) / 2 stop start f f + span f = stop start f f − Center Freq Set the center frequency of the current channel.
Press this key to switch to center frequency input mode and the center frequency is displayed at the lower left and right sides of the grid respectively. Key Points: • The start and stop frequencies vary with the center frequency when the span is constant. • Changing the center frequency horizontally shifts the current channel and the adjustment is limited by the specified frequency range. • In Zero Span mode, the start frequency, stop frequency and center frequency are always the same. • You can modify this parameter using the numeric keys, knob or direction keys. Refer to “ Parameter Setting ” for more details. Center Frequency *Note:
The range is from 50 Hz to [3.2 GHz (1.6GHz)-50 Hz] in non-zero span. Start Freq Set the start frequency of the current channel. Press this key to switch to start/stop frequency input mode and the start and stop frequencies are displayed at the lower left and right sides of the grid respectively. Key Points: • The span and center frequency vary with the start frequency. The change of span would affect other system parameters. For more details, please refer to “ Span ”. Parameter Explanation Default 3.2 GHz (1.6GHz) Range* 0 Hz to 3.2 GHz (1.6GHz) Unit GHz, MHz, kHz, Hz Knob Step Span > 0, step = Span/200 Span = 0, step = RBW/100 Min = 1 Hz Direction Key Step CF step