Vector Network Analyzer (VNA) Measurement Guide : VNA Calibration and Measurements : Setting Scale Parameters
 
Setting Scale Parameters
The SCALE parameters corresponds to the y-axis display. The instrument supports both log units (such as dBm and dBV) and linear units of scale (such as volts or watts). Amplitude-related parameters are set using the SCALE Menu.
Setting Resolution and Reference Line
This setting applies to most analyzer modes of operation and allows you to set the y-axis graticule scale for log-based units only.
1. Select SCALE > RESOLUTION.
2. Enter the desired number
3. Select SCALE > REF LINE
4. Enter the desired number
SCALE Menu
Access the SCALE menu from the main menu.
SCALE Menu
 
DRAG
Toggles the touchscreen drag feature on or off. When toggled off, the reference level will not change when dragging the display. This can be useful when dragging markers.
PINCH
Toggles the touchscreen pinch feature on or off. When toggled off, the resolution will not change when pinching the display. This can be useful when dragging markers.
REF LEVEL
The reference level is the top graticule line on the measurement display. If the reference level offset is not zero, the offset reference level is displayed at this location. Selecting the plus (+) or minus (–) control increments the value by 10. The plus/minus (+/-) button on the keypad toggles between positive and negative values.
RESOLUTION
Sets the number of units that are displayed between horizontal reticle lines. Units depend upon frequency, time, and distance settings. The default resolution is 10 dB.
REF LINE
Sets the horizontal graph reticle at the reference level. The reference line is indicated by a yellow line with small triangle heads on both sides. Reference line is 9 by default is 9 and the max is 10. The position is adjusted based on the set value.
 
APERTURE
Aperture percentage is available only when the GRAPH TYPE is set to GROUP DELAY. Group delay is a measurement of “Change in phase / change in frequency.” The aperture setting is used by the Site Master to determine how large a change in frequency to use in this calculation.
AUTO SCALE
Adjusts the resolution and reference level so that the active trace for the current measurement is shown in the middle of the display.
FULL SCALE
Sets the resolution to 10 dB and reference level to zero.
PRESET
Presets all the scale parameters.
SCALE Menu (Smith Chart)
To access Smith Chart’s SCALE menu go to main menu, MEASURE > GRAPH TYPE > Smith.
SCALE Menu (Smith Chart)
 
SMITH SCALE
Allows expansion and compression of the scale with respect to the reference impedance. Select any of the available expand and compress options to view the smith chart in a desired manner.
REF IMPEDANCE
Sets the reference impedance as either 50 ohms or 75 ohms.