Configure Traces

The NanoVNA-H supports up to 4 simultaneous traces, each displaying different measurements from either the S11 (reflection) or S21 (transmission) channel. This guide shows how to configure traces for your measurement needs.

Understanding Traces

Each trace consists of three settings:

Channel: S11 (CH0, reflection) or S21 (CH1, transmission)
Format: How data is displayed (LogMag, Phase, Smith, SWR, etc.)
Scale/Reference: Vertical scaling and reference position

Enable or Disable Traces

Tap the screen to open the menu
Navigate to DISPLAY > TRACE
Tap the trace you want to toggle (TRACE 1-4)
The selected trace toggles between enabled and disabled

Change Trace Channel

Open the menu and go to DISPLAY
Tap CHANNEL to cycle between S11 and S21
This affects the currently selected trace

To change a specific trace’s channel:

Go to DISPLAY > TRACE and tap the desired trace to select it
Return to DISPLAY and tap CHANNEL

Change Trace Format

For S11 (reflection) measurements, navigate to DISPLAY > FORMAT S11 (REFL):

Format	Description	Typical Use
LOGMAG	Logarithmic magnitude (dB)	Return loss, attenuation
PHASE	Phase angle (degrees)	Phase response
DELAY	Group delay (seconds)	Filter analysis
SMITH	Smith chart	Impedance matching
SWR	Standing wave ratio	Antenna tuning
RESISTANCE	Real impedance (ohms)	Component measurement
REACTANCE	Imaginary impedance (ohms)	Component measurement
\|Z\|	Impedance magnitude	Component measurement

Additional S11 formats in MORE:

POLAR, LINEAR, REAL, IMAG
Q FACTOR, CONDUCTANCE, SUSCEPTANCE, |Y|
Z PHASE, SERIES C, SERIES L
PARALLEL R, PARALLEL X, PARALLEL C, PARALLEL L

For S21 (transmission) measurements, navigate to DISPLAY > FORMAT S21 (THRU):

Format	Description	Typical Use
LOGMAG	Insertion loss (dB)	Filter response
PHASE	Transmission phase	Phase shift
DELAY	Group delay	Filter analysis
SMITH	S21 Smith chart	Matching networks
POLAR	Polar display	Complex S21
LINEAR	Linear magnitude	Gain

Additional S21 formats in MORE:

SERIES R, SERIES X, SERIES |Z|
SHUNT R, SHUNT X, SHUNT |Z|
Q FACTOR

Shell Commands for Traces

Configure traces via serial console:

# Set trace format
trace {0|1|2|3} {format}

# Available formats:
# logmag|phase|delay|smith|polar|linear|swr|real|imag|
# r|x|z|zp|g|b|y|rp|xp|sc|sl|pc|pl|q|
# rser|xser|zser|rsh|xsh|zsh|q21

# Examples:
trace 0 logmag    # Set trace 0 to log magnitude
trace 1 smith     # Set trace 1 to Smith chart
trace 2 swr       # Set trace 2 to SWR
trace 3 phase     # Set trace 3 to phase

# Set trace channel (0=S11, 1=S21)
trace 0 logmag 0  # Trace 0, logmag, S11 channel

# Set scale and reference position
trace 0 scale 10      # 10 dB/div
trace 0 refpos 7      # Reference at position 7 (of 8)

Stored Trace

The NanoVNA-H can store one trace for comparison:

Go to DISPLAY > TRACE
Tap STORE TRACE to capture current trace data
Tap again to toggle display of stored trace

Stored traces appear in a different color and remain static while live traces update.

Default Trace Configuration

The default setup shows:

Trace 0: S11 LogMag (yellow)
Trace 1: S21 LogMag (cyan)
Trace 2: S11 Smith (green)
Trace 3: S21 Phase (magenta)

NanoVNA-H display with all four traces active: LOGMAG (yellow), SWR (cyan), Smith chart (magenta), and Phase (green)

Trace Format Examples

Here is how each common format looks on the display:

LOGMAG — Logarithmic magnitude in dB. The most common format for viewing return loss (S11) or insertion loss (S21).

NanoVNA-H LOGMAG trace showing S11 and S21 magnitude in dB from 100 to 200 MHz

SWR — Standing wave ratio. Shows the impedance mismatch as a ratio, commonly used for antenna tuning.

NanoVNA-H SWR trace display showing standing wave ratio for S11

Smith Chart — Normalized impedance on a circular grid. Essential for impedance matching work.

NanoVNA-H Smith chart display showing S11 impedance

Phase — Phase angle in degrees. Shows how the phase of the reflected or transmitted signal varies with frequency.

NanoVNA-H Phase trace display showing S11 phase angle across frequency