Using Markers

Markers allow you to read precise values at specific frequencies. The NanoVNA-H supports up to 8 markers (hardware dependent), each displaying frequency and measurement values.

Enable Markers

1. Tap the screen to open the menu
2. Navigate to MARKER
3. Tap SELECT MARKER and choose a marker (1-8)
4. The selected marker becomes active and visible

Note

Marker 1 is enabled by default. Additional markers must be enabled manually.

Position Markers

Using Touch Screen

1. Ensure the desired marker is selected (active)
2. Tap directly on the trace where you want the marker
3. The marker moves to the nearest sweep point

Using Menu

1. Go to MARKER > SELECT MARKER and choose a marker
2. Return to MARKER menu
3. Use MARKER FREQ to enter an exact frequency
4. Enter the frequency value and tap the appropriate unit

Marker Readout

When markers are active, the screen displays:

• Frequency: The marker position in Hz/kHz/MHz
• Primary value: Depends on the trace format (dB, degrees, ohms, etc.)
• Secondary values: Additional parameters like R+jX for Smith chart

The marker info panel shows all enabled markers with their current readings.

Select Active Marker

1. Go to MARKER > SELECT MARKER
2. Tap the marker number (1-8) to make it active
3. The active marker is highlighted in the marker panel

The active marker determines which marker moves when you tap the screen or enter a frequency.

Disable Markers

To hide a marker:

1. Go to MARKER > SELECT MARKER
2. Tap the marker you want to disable
3. Tap MARKER OFF to hide it

Or use ALL OFF to disable all markers at once.

Marker Operations

Set Marker to Center

1. Position marker at the frequency of interest
2. Go to MARKER > MARKER->CENTER
3. The sweep center frequency moves to the marker position

Set Marker to Span Start/Stop

• MARKER->START: Sets sweep start to marker frequency
• MARKER->STOP: Sets sweep stop to marker frequency

Shell Commands

# Enable marker n at index position
marker n on
marker n {index}

# Disable marker
marker n off

# Enable all markers
marker on

# Disable all markers
marker off

# Examples:
marker 1 on        # Enable marker 1
marker 2 100       # Enable marker 2 at sweep point 100
marker 3 off       # Disable marker 3

Marker Display Format

The marker readout format depends on the trace type:

Trace Format	Marker Shows
LogMag	dB value
Phase	Degrees
SWR	Ratio (e.g., 1.5:1)
Smith	R + jX ohms
Delay	Seconds
Impedance	Ohms

For Smith chart traces, the marker can show additional formats (see Smith Marker Formats guide).

Marker Precision

Markers snap to the nearest sweep point — they cannot land between points. This means marker frequency accuracy depends on your sweep configuration:

Sweep Range	Points	Frequency Resolution
100–200 MHz	101	1.0 MHz per point
100–200 MHz	401	0.25 MHz per point
140–150 MHz	101	100 kHz per point
144–148 MHz	101	40 kHz per point

For precise frequency readings, narrow the sweep range around the frequency of interest. The NanoVNA-H4’s 401 points gives four times finer resolution than the NanoVNA-H’s 101 points.

Tip

Use MARKER→CENTER to re-center the sweep on the marker, then reduce the span. Repeat to zoom in progressively for maximum precision.

Multiple Marker Strategies

Use multiple markers for comparative measurements:

Bandwidth Measurement

1. Marker 1 at the passband center (minimum S11 or maximum S21)
2. Markers 2 and 3 at the -3 dB points on each side
3. Read bandwidth as the frequency difference between markers 2 and 3

Filter Shape Factor

1. Markers 1-2 at the -3 dB bandwidth edges
2. Markers 3-4 at the -60 dB points
3. Shape factor = (-60 dB bandwidth) / (-3 dB bandwidth)

Antenna Comparison

1. Place markers at key operating frequencies (e.g., 144.0, 145.0, 146.0, 148.0 MHz)
2. Read SWR at each point simultaneously
3. Compare before and after adjustments without repositioning

Markers Across Trace Formats

When multiple traces are active, a single marker reads values from every enabled trace simultaneously. The marker readout panel shows all values stacked:

Trace	Marker Shows
S11 LogMag	Return loss in dB
S11 Smith	R + jX in ohms
S21 LogMag	Insertion loss in dB
S21 Phase	Phase shift in degrees

This is one of the NanoVNA’s most useful features — you can see impedance, return loss, and insertion loss at the same frequency without switching views.

Lever Mode

When lever mode is set to MARKER (default), the hardware jog wheel moves the active marker position. Turn the wheel to step through sweep points one at a time. Change the lever mode via CONFIG > LEVER MODE:

Mode	Jog Wheel Controls
MARKER	Active marker position
SPARAMETER	Not used (reserved)
CALIBRATE	Not used (reserved)

Marker Tracking

The active marker tracks across sweeps, maintaining its frequency position as data updates. This is useful for:

• Tuning antennas in real-time: Watch the marker readings update as you adjust element length
• Temperature drift monitoring: See how a crystal or filter shifts over time
• Before/after comparisons: Same marker position, different DUT

Caution

When changing the sweep range, markers may need repositioning if their frequency falls outside the new range. Markers outside the sweep appear at the nearest edge point with potentially misleading readings.

Troubleshooting

Marker Readout Shows Wrong Units

The marker displays values in the units of the active trace format. If you see dB when expecting ohms, check which trace is selected — tap the trace indicator to switch.

Marker Jumps When Changing Active Marker

Each marker has its own position. When you switch active markers, the readout changes to show that marker’s frequency. The jog wheel now moves the newly selected marker.

All Markers Disappeared

Check MARKER > SELECT MARKER — markers may have been disabled with ALL OFF. Also verify the markers are within the current sweep range.