Hardware Variants

The NanoVNA-H family has two models — the original NanoVNA-H and the larger NanoVNA-H4 — built around different STM32 microcontrollers. Both run the same firmware codebase and share identical measurement architecture, but differ in display size, processing power, and sweep resolution.

This page helps you identify which device you have and understand the differences that matter for measurement.

NanoVNA-H vs NanoVNA-H4

Feature	NanoVNA-H	NanoVNA-H4
MCU	STM32F072CBT6	STM32F303CCT6
CPU Core	ARM Cortex-M0, 48 MHz	ARM Cortex-M4, 72 MHz
FPU	None (software float)	Hardware single-precision
Flash	128 KB	256 KB
RAM	16 KB	40 KB
Display	2.8” (320×240)	4.0” (480×320)
LCD Controller	ILI9341 or ST7789	ST7796S
Max Sweep Points	101	401
Calibration Slots	5	7
USB Connector	Micro-USB	USB Type-C
Approx. Size	91 × 60 × 15 mm	130 × 83 × 20 mm
Frequency Range	600 Hz – 2 GHz	600 Hz – 2 GHz
Dynamic Range	> 70 dB (direct)	> 70 dB (direct)
Port Impedance	50 Ω (SMA)	50 Ω (SMA)

When the Differences Matter

Sweep points are the most impactful difference. 101 points across a wide frequency range gives you coarse resolution — fine for antenna SWR, but limiting for narrow-band filter measurements. 401 points on the H4 resolves details four times finer.

Display size matters for field use. The H4’s 480×320 screen shows more trace detail and makes the Smith chart easier to read, especially without reading glasses.

Processing speed affects sweep time at narrow bandwidths. The H4’s Cortex-M4 with hardware FPU handles DSP calculations faster, though both models sweep at similar speeds at default bandwidth settings.

Memory determines how much calibration and measurement data can be stored. The H4 stores 7 calibration slots with larger property blocks (16 KB vs 6 KB per slot), allowing more saved configurations.

Identifying Your Device

From the Firmware

Connect via USB and send the info command:

NanoVNA-H
NanoVNA-H4

ch> info
Board: NanoVNA-H
Version: 1.2.44 [p:101, IF:12k, ADC:192k, Lcd:320x240]
Architecture: ARMv6-M Core Variant: Cortex-M0
Platform: STM32F072xB

Key identifiers: ARMv6-M, Cortex-M0, STM32F072xB, 320x240

ch> info
Board: NanoVNA-H4
Version: 1.2.44 [p:401, IF:12k, ADC:192k, Lcd:480x320]
Architecture: ARMv7E-M Core Variant: Cortex-M4
Platform: STM32F303xC

Key identifiers: ARMv7E-M, Cortex-M4, STM32F303xC, 480x320

From the PCB

Look for the revision marking printed on the circuit board edge:

NanoVNA-H: Labeled NanoVNA-H v3.x (e.g., v3.4, v3.6, v3.7)
NanoVNA-H4: Labeled NanoVNA-H4 v4.x (e.g., v4.3, v4.4)

At a Glance

If the display is about 2.8 inches and the USB port is Micro-USB, you have the NanoVNA-H. If the display is about 4 inches and the USB port is Type-C, you have the NanoVNA-H4.

Mixer IC Variants

Both models use a mixer IC to downconvert the RF signal. Two mixer ICs have been used across production runs, and they affect the minimum frequency and harmonic threshold:

Mixer IC	Manufacturer	Status	Min Frequency	Harmonic Threshold
SA612A	NXP	Discontinued	1.6 kHz	~290 MHz
NE602A	ZeeTK	Current production	600 Hz	~300 MHz

The ZeeTK NE602A is a pin-compatible replacement introduced after NXP discontinued the SA612A. While electrically similar, the different manufacturing process changes harmonic behavior, which is why newer board revisions (3.7, 4.4) include modified component values in the mixer section.

Which Mixer Do I Have?

Check the minimum frequency in the info output or look at the IC markings on the PCB near the SMA connectors:

SA612A (NXP logo): Older units, rev 3.4–3.6 and rev 4.3
NE602A (ZeeTK marking): Newer units, rev 3.7+ and rev 4.4+

Frequency Synthesizer Variants

The signal source has evolved across production runs. All variants are register-compatible with the Silicon Labs Si5351A:

Variant	Introduced	Notes
Si5351A	Rev 3.4	Original Silicon Labs part
MS5351M	Rev 3.5	Chinese compatible; some units have limited VCO lock range
SMC5351	Rev 3.6.1	Lower power, better isolation; renamed to SJWCH5351
SJWCH5351	Rev 3.7+	Current production part (same as SMC5351)

The firmware handles all these transparently. The main practical difference is that some MS5351 units cannot lock their VCO at certain frequencies, causing measurement spikes near 588 MHz. The SJWCH5351 resolves this and also provides better port-to-port isolation below 300 MHz.

For full details, see Synthesizer Variants.

Board Revision Timeline

timeline
  title NanoVNA-H Hardware Revisions
  section NanoVNA-H
      Rev 3.4 : Initial widely-available hardware
              : STM32F072, ILI9341, SA612A
      Rev 3.5 : Improved power management
              : MS5351M support
      Rev 3.6 : ST7789 display auto-detection
              : SMC5351 support
      Rev 3.6.1 : SMC5351 synthesizer
                : Improved port isolation
      Rev 3.7 : ZeeTK NE602A mixer
              : SJWCH5351, 600 Hz minimum
  section NanoVNA-H4
      Rev 4.3 : Initial H4 release
              : STM32F303, ST7796S, SA612A
      Rev 4.4 : ZeeTK NE602A mixer
              : SJWCH5351, 401 sweep points

NanoVNA-H Revisions

Revision	Key Changes
3.4	Initial production. STM32F072, ILI9341 display, SA612A mixer.
3.5	Improved power management, enhanced codec configuration.
3.6	Added ST7789 display controller support (auto-detected at boot).
3.6.1	SMC5351 synthesizer with lower power and better port isolation.
3.7 (current)	ZeeTK NE602A mixer, SJWCH5351 synth, operates down to 600 Hz.

NanoVNA-H4 Revisions

Revision	Key Changes
4.3	Initial H4 release. STM32F303, 4” ST7796S display, SA612A mixer.
4.4 (current)	ZeeTK NE602A mixer, SJWCH5351 synth, refined DAC backlight control.

Display Controller Variants

The NanoVNA-H firmware auto-detects the display controller at boot. You do not need to configure anything — just be aware that two display controllers may be present in NanoVNA-H units:

Controller	Resolution	Used In
ILI9341	320×240	NanoVNA-H (all revisions)
ST7789	320×240	NanoVNA-H (rev 3.6+)
ST7796S	480×320	NanoVNA-H4 (all revisions)

The ILI9341 and ST7789 are functionally interchangeable from the user’s perspective. The firmware handles the differences in initialization and pixel readback internally.

For full display technical details, see Display Controllers.

Firmware Compatibility

You must flash the correct firmware binary for your hardware:

Device	Build Command	Output Binary	Key Defines
NanoVNA-H (SA612A)	`make`	`build/H.bin`	—
NanoVNA-H (ZeeTK)	`make`	`build/H.bin`	`__ZEETK__` enabled
NanoVNA-H4 (SA612A)	`make TARGET=F303`	`build/H4.bin`	—
NanoVNA-H4 (ZeeTK)	`make TARGET=F303`	`build/H4.bin`	`__ZEETK__` enabled

The __ZEETK__ define in nanovna.h controls:

Minimum frequency (600 Hz vs 1.6 kHz)
Harmonic threshold (300 MHz vs 290 MHz)
Mixer-specific tuning parameters

Pre-built firmware binaries from NanoVNA.com are typically compiled with __ZEETK__ for the current production hardware. If you have older SA612A hardware, you may need to build from source with that define commented out.

Which Model Should I Get?

If you are choosing between the two:

Choose the NanoVNA-H if:

You want the most compact form factor
You primarily measure antennas (101 points is usually sufficient for SWR)
Budget is a priority

Choose the NanoVNA-H4 if:

You measure filters, crystals, or other narrow-band devices (401 points matters)
You want a larger, more readable display
You prefer USB Type-C
You plan to do firmware development (more flash/RAM, hardware FPU)

Both are excellent instruments for the price. The measurement accuracy, once calibrated, is comparable.