 | Top Press this submenu key to set the top amplitude value in the trace window. Use the virtual keypad to enter the value in the edit box, then press the dB key or Enter to apply the new power level and close the edit box. To exit without making a change, press Esc to cancel the entry, and Esc again to close the edit box. Bottom This key sets the bottom amplitude value in the trace window. Use the keypad to enter the value in the edit box, then press the dB key or Enter to apply. Autoscale Automatically sets the top and bottom scales to the minimum and maximum values of the measurement with some margin on the y-axis of the display. The AutoScl (.) keypad key performs the same function. Fullscale: Fullscale automatically sets the scale to the default setting. 0 dB to 60 dB for Return Loss measurements, 0 to 30 dB for Cable Loss, and 1 to 65 for VSWR measurements. When measurement results are displayed in a Smith Chart, the Amplitude menu consists of a single key: Ref. Impedance 50 Ω 75 Ω Sets the reference impedance that is used for Smith Chart calculations to either 50 Ω or 75 Ω. The reference impedance determines the value of impedance at the center of the Smith Chart. Figure: Set Reference Impedance for Smith Chart Measurement illustrates a Smith Chart measurement, shown in dual display format. |
