Also known as: NanoVNA, NanoVNA-H, NanoVNA-F
The NanoVNA is a low-cost, open-source handheld vector network analyzer that brought S-parameter measurement — antenna SWR, return loss, filter response, and cable checks — down to a pocket-sized, sub-$100 instrument.12 Originally designed by “edy555” (Tomohiro Takahashi) and since forked into many hardware and firmware variants, it has become the default antenna analyzer for radio amateurs and SDR hobbyists.
What it is
Under the hood the NanoVNA is a full — if modest — two-port VNA. A Si5351 clock generator synthesizes the test tone (with harmonics extending the usable range above the chip’s fundamental limit), an SA612 mixer and resistive bridge separate incident from reflected waves, and a microcontroller sweeps frequency while sampling amplitude and phase. CH0 performs reflection (S11 — SWR, return loss, impedance) and CH1 performs transmission (S21 — insertion loss or gain). Results appear on a small touchscreen and can be logged to a PC over USB for Smith-chart and Touchstone export.
Variants
The open design has spawned a family of boards. The NanoVNA-H and -H4 are the common improved originals (2.8” and 4” displays); the NanoVNA-F and -F V2 use metal cases and better screens; and the NanoVNA V2 / SAA-2N and later “LiteVNA” and “NanoVNA-F V3” designs raise the top frequency to roughly 3–6 GHz with improved dynamic range. The baseline units cover about 50 kHz to 1.5 GHz, which comfortably spans the HF, VHF, and UHF bands where most trunking and scanner antennas live.
In practice
Like any VNA, a NanoVNA is only as good as its calibration: you run a SOLT (Short-Open-Load-Through) cal at the ends of your test leads before every serious measurement, and re-cal whenever you change the frequency span or cabling. Its limitations relative to a bench instrument are real — modest dynamic range, more measurement noise, and less accuracy at the top of its range — but for setting up an antenna, checking a filter, or sanity-checking coax it is remarkably capable for the price. A companion tinySA covers the spectrum-analysis side.
Relevance to SDR
For SDR scanning the NanoVNA is the practical tool for the job the VNA entry describes: confirm your discone, dipole, or whip is resonant on the band you care about, minimize SWR, and verify that any inline filter passes the target frequencies and rejects out-of-band interferers before they reach the SDR front end. GopherTrunk does not talk to a NanoVNA — it is a receive-only decoder — but a NanoVNA is the low-cost bench aid most GopherTrunk users reach for when building or tuning their antenna and feedline.
Sources
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NanoVNA — Wikipedia, on the NanoVNA open-source handheld vector network analyzer and its variants. ↩
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nanovna.com — project and community hub for NanoVNA hardware, firmware, and usage guidance. ↩