Antennas · Volume 25
Other Antenna Analyzers & VNAs
RigExpert (Stick / AA-600 / AA-2000), MFJ-259/269, Sark-110, Comet CAA-500, the full-instrument VNAs (Keysight / R&S / Copper Mountain), and where each sits relative to the NanoVNA
Contents
1. About this volume
Vol 24 (NanoVNA Deep Dive) covered the open-source two-port reflectometer that, since the NanoVNA-H landed in 2019, has redefined the price/capability floor for antenna measurement at HF through low microwave. This volume covers everything else: the commercial single-port amateur analyzers that predated the NanoVNA and still occupy a defensible market niche (RigExpert, MFJ, Comet), the design that bridged the eras (Sark-110), and the full-instrument VNAs whose specifications the NanoVNA can asymptote toward but cannot match (Keysight FieldFox + benchtop E5063A/E5071C, R&S ZNL, Copper Mountain S-series, and the legacy HP 8753 family that anchors the used-VNA market).
For 80 % of the antenna and matching-network work covered in Vols 6-19, a NanoVNA-H V3 plus a $300 Pasternack cal kit is fully sufficient and will outperform a $400 MFJ-259D on every measurement that has phase information in it. The remaining 20 % — filter shape factor below the -60 dB stopband, calibrated absolute power, group-delay measurements with picosecond accuracy, sub-0.1° phase repeatability over a temperature swing, NIST-traceable verification — is where the analyzer-vs-VNA distinction in §2 and the dynamic-range and stability arguments in §7 start to matter, and where $3k-$50k on commercial gear stops looking absurd. §8 puts the decision in matrix form. §9 and §10 are the buyer’s-guide sections; most readers underestimate cal-kit cost relative to instrument cost, and §10 quantifies it.
2. Antenna analyzer vs VNA — what’s the difference
The functional distinction is which subset of the 2-port S-parameter matrix the instrument measures. A classical antenna analyzer is a 1-port reflectometer: it stimulates the device under test with a swept sine, measures the magnitude (and on better units, the phase) of the reflected wave, and computes return loss, VSWR, complex impedance R+jX, and from R+jX, anything derivable (reflection coefficient Γ, return loss in dB, mismatch loss, equivalent series capacitance or inductance at a single frequency). It cannot measure anything about a signal that goes through a device — no insertion loss, no filter shape, no amplifier gain, no isolation, no group delay. The math it does is the Smith-chart math from Vol 4 §4 and that is the boundary of its world.
A vector network analyzer measures all four S-parameters of a 2-port device — S11 (reflection at port 1), S21 (transmission from port 1 to port 2), S12 (reverse transmission), and S22 (reflection at port 2). With both ports calibrated, the instrument can characterize anything with two ports: filters (S21 magnitude is the response, S21 phase is the group delay derivative), amplifiers (S21 magnitude is small-signal gain, S11 and S22 are the input and output match), BALUNs (S21 is the insertion loss, the common-mode rejection is measured by a special connection topology covered in Vol 16), couplers (S21, S31, S41 are the through, coupled, and isolated paths), antennas (still 1-port, but now with phase, so TDR works — see Vol 24), and any cascade thereof. The 2-port matrix is the lingua franca of RF; with it, the instrument can do everything the analyzer can do plus everything the analyzer cannot.
Historically, the line between the two categories was hard. A 1990s MFJ-259 was an SWR/R/X bridge with a frequency counter, no phase information, $300, and amateur-targeted. A contemporaneous HP 8753C was a full benchtop VNA — 30 kHz to 6 GHz, 90 dB dynamic range, GPIB-controllable, $30,000-$50,000 new, lab-targeted. The intermediate category — RigExpert AA-series in the 2000s, Sark-110 in 2015 — gradually filled in 1-port plus limited 2-port capability at the $400-$800 price point, but the line remained: under $1k was amateur analyzers, over $5k was real VNAs, and the space between was thinly populated.
The NanoVNA blew this up. A $60 NanoVNA-H is a true 2-port VNA (S11/S21 measured directly, S12/S22 via DUT swap), with 50-80 dB dynamic range, swept 50 kHz to 1.5 GHz, OSL+through calibration, USB host control, and an open hardware design. The LiteVNA-64 extends to 6 GHz for $250. At 2026-05 prices the NanoVNA family does everything a $2k 2017-era RigExpert AA-2000 Zoom did plus more, with broadly comparable raw measurement accuracy at HF and within a factor of 2-3 dB of accuracy at VHF/UHF. The category-killer effect is real.
What survives the NanoVNA on the analyzer side is ergonomics, polish, and ruggedization — the user interface and physical form factor reasons the §3-§6 instruments still sell in 2026, covered there. What survives on the VNA side is dynamic range, phase accuracy, calibration traceability, and absolute-power capability — the §7 reasons that a Keysight E5071C or R&S ZNL-3 is not “just a more expensive NanoVNA” but a fundamentally different measurement instrument, covered there.
Things a NanoVNA cannot do that push a serious workflow toward a bench instrument: (a) deep stopband measurements below about -60 dB — a 7th-order helical filter with 90 dB ultimate rejection looks like a 60 dB filter on a NanoVNA because the instrument’s internal isolation and ADC dynamic range bottom out there; (b) calibrated absolute power — the NanoVNA’s port-1 output is nominally -10 dBm but actual value drifts with temperature and unit-to-unit variation is several dB, so “feed this antenna with exactly 100 mW RMS” is not a NanoVNA measurement; (c) phase accuracy under 0.1°, limited by the $0.50 TCXO reference with phase noise of -80 to -100 dBc/Hz; (d) NIST-traceable measurements for FCC certification, EMC testing, or defense work; (e) stable measurements over wide temperature swings — bench VNAs use oven-stabilized references and temperature-compensated bridges; the NanoVNA’s bridges drift with temperature. For typical antenna and matching-network work, none of (a)-(e) is a forcing function; for the subset where one is, the rest of this volume covers the step-up options.
3. RigExpert AA-Stick / AA-230 / AA-600 / AA-2000
Ukrainian vendor RigExpert (Rig Expert Ukraine Ltd., Kyiv) has been the premium amateur analyzer manufacturer since ~2010, when the AA-30 and AA-54 displaced the MFJ-259 series at the top of the amateur market. The 2026 lineup divides into standalone “Zoom” units (color screens, battery-powered, 1-port, no PC), PC-tethered USB sticks (smaller, no display, laptop test heads), and the high-end AA-2000 Zoom which extends standalone operation to 2 GHz.
| Model | Frequency range | Screen | Standalone? | TDR | Sweep memory | Price (mid-2026 USD) |
|---|---|---|---|---|---|---|
| AA-35 Zoom | 60 kHz – 35 MHz | 2.4” color TFT | yes (4× AA NiMH) | yes | 100 charts | $300 |
| AA-55 Zoom | 60 kHz – 55 MHz | 2.4” color TFT | yes (4× AA NiMH) | yes | 100 charts | $370 |
| AA-230 Zoom | 100 kHz – 230 MHz | 2.4” color TFT | yes (4× AA NiMH) | yes | 100 charts | $430 |
| AA-600 | 100 kHz – 600 MHz | 2.4” color TFT | yes (4× AA NiMH) | yes | 100 charts | $590 |
| AA-2000 Zoom | 100 kHz – 2000 MHz | 3.2” color TFT | yes (Li-ion internal) | yes | 100 charts | $900 |
| AA-Stick Pro | 0.1 – 1300 MHz | none (PC required) | no | via PC | via PC | $300 |
The “Zoom” branding refers to the dual-rotary-encoder zoom-and-pan navigation introduced around 2017 — pick a center frequency and span, sweep, then zoom into any region without re-typing limits. On a battery-powered field instrument this is faster than the NanoVNA workflow of menu navigation or tethered NanoVNA-Saver. The AA-230 Zoom is RigExpert’s volume leader — 0.1-230 MHz covers 160 m through 2 m amateur bands plus VHF marine and aviation. The AA-600 adds 70 cm amateur and 150-174 / 450-512 MHz public-safety / commercial bands, where it’s most often deployed. The AA-2000 Zoom extends to 2 GHz — cellular bands (PCS 1900, AWS 1700/2100), amateur 13 cm partial coverage (2300-2310 and 2390-2450 MHz at band edge); 2.4 GHz Wi-Fi / Bluetooth need careful interpretation because top of band at 2.485 GHz is above the 2.0 GHz upper limit. The AA-Stick Pro is the same RF front-end as the AA-2000 Zoom in a USB-only package without screen, encoder, or battery — at $300 vs $900 it trades standalone field-instrument capability for portability and price; most useful as a laptop-bag second analyzer.
What RigExpert does better than a NanoVNA: (1) Polished UI — dedicated SWR / Smith / R+X / TDR display modes accessed by hardware buttons, forgiving for the operator who hasn’t touched the instrument in three months. The NanoVNA’s menu is functional but assumes muscle memory. (2) Daylight-readable screens — 2.4” or 3.2” transflective TFT designed for outdoor visibility, vs the NanoVNA-H V3’s IPS which washes out in direct sun. For tower work this is the single most important ergonomic difference. (3) Battery life 6-8 hours on 4× AA NiMH (Eneloop), vs 2-4 hours on the NanoVNA-H’s internal Li-ion. (4) Calibration retention across power cycles — RigExperts store cal in non-volatile flash valid until ports change; NanoVNA cal is lost on every power cycle unless explicitly saved to one of 5 slots. Saves 5-10 minutes per session on multi-day field deployments. (5) Ruggedization — glass-filled nylon chassis, panel-mount BNC with metal backshell, will survive being dropped on a concrete tower base; NanoVNA’s SMA connectors and plastic case will not.
Where RigExpert is matched by or worse than a NanoVNA: (1) No 2-port capability — Zoom units (and the Stick Pro) are 1-port only. Cannot measure filter S21, BALUN insertion loss, amplifier gain, or anything else that needs through measurement. For 2-port work the NanoVNA is mandatory and the RigExpert is wrong tool. (2) Cost per GHz — the NanoVNA wins by an order of magnitude ($60 for 50 kHz – 1.5 GHz vs $900 for 100 kHz – 2 GHz). (3) TDR resolution is similar at HF/VHF; the AA-2000 Zoom is slightly better at UHF, marginal for cable fault-finding.
Practical decision: for single-antenna field measurement on towers where a sealed handheld with a daylight screen is genuinely useful, the AA-230 Zoom or AA-600 is worth the $430-590 over the NanoVNA. For mixed antenna + matching-network + filter + amplifier work at a bench, the NanoVNA is more capable despite worse ergonomics, and the $400-800 saved buys a much better cal kit (§10), which is where measurement quality actually comes from.
4. MFJ-259 / 269 — the legacy classics
The MFJ-259 was, in 1995, the first widely-available antenna analyzer at consumer amateur price points. Before it, antenna SWR measurement meant a wattmeter and a transmitter — keying up at the antenna base or reading SWR back at the shack. The 259 packaged a 1.8-170 MHz sweep oscillator, a resistive SWR bridge, and an LCD into a battery-powered handheld at $250 new. It defined the amateur antenna analyzer category for the next 20 years.
Revisions ran through 259, 259B, 259C, 259D, with the D being the final and most-deployed version (manufactured ~2005 through MFJ’s 2023 shutdown). The MFJ-269D extended frequency coverage to 230-470 MHz on a second internal oscillator (selectable front-panel switch), making it the first amateur analyzer to cover 70 cm and public-safety UHF without external block converters. 259D and 269D are the units found on the used market today.
Specs in brief: 259D covers 1.8-170 MHz; 269D covers 1.8-230 plus 415-470 MHz. Continuous frequency knob mechanically coupled to a varactor (turn the knob, frequency moves). 4-digit LCD displaying one of {frequency, SWR, R, X, return-loss-dB, capacitance-pF-at-resonance, inductance-µH-at-resonance, distance-to-fault-feet}. No PC interface, no data export, no internal memory. 10× AA batteries for ~10 hours. $400 new (259D) / $500 new (269D) at MFJ’s final pricing. Build quality is genuinely good — metal chassis, panel-mount BNC, large knobs for gloved operation, schematic published in the manual. Repairable to component level with a multimeter and a soldering iron.
What the 259D/269D cannot do: (1) measure phase — R and X are derived from magnitude-only bridge measurements; no Smith chart, no TDR, no meaningful S21, no accurate characterization of a complex network. (2) export data — every measurement is a one-at-a-time LCD read; no serial, USB, or Bluetooth. (3) sweep automatically — the frequency knob is mechanical, so sweeping means turning the knob and watching SWR change (5-10 seconds across 1.8-30 MHz, fast but not data-loggable).
Why someone might still buy one in 2026: (1) indestructibility — the unit is mechanically rugged, with no screen-based UI to break; a 259D from 2005 will still work in 2050. (2) knob workflow is faster for “find this antenna’s resonant frequency” than the NanoVNA’s sweep-marker-zoom dance, particularly for tower technicians trimming dipoles. (3) used-market price — clean 259D at $200-300, 269D at $275-375. Defensible as a field-bag second analyzer or backup when the NanoVNA’s screen or battery dies. (4) no firmware, no software, no driver compatibility issues — works on its own forever.
What to verify on a used purchase: frequency counter calibration (counter drifts a few hundred Hz over years, re-calibrated via back-panel trimmer), bridge balance (measure a known 50 Ω load and verify R=50, X=0, SWR=1.00), battery contacts (spring-loaded AA contacts corrode over storage). MFJ shut down 2023 — no factory service. Third-party W4RT Electronics handled most repairs until they also closed 2024. Schematic is in the manual and parts (varactors, op-amps, LCD) are standard through-hole from Mouser/DigiKey, so any competent ham with a multimeter and oscilloscope can troubleshoot.
Bottom line in 2026: not a primary instrument, not recommended new even if MFJ were still selling them, but defensible $200-300 used for a redundant field analyzer, intro teaching tool for a new ham, or backup-for-when-the-NanoVNA-dies. Historical value high, practical value narrow.
5. Sark-110 — pocket VNA precursor to NanoVNA
The Sark-110 is Spanish engineer Melchor Varela’s 2014-era design that genuinely bridged the analyzer and VNA categories at consumer price points, four years before the NanoVNA-H made the bridge obsolete. A 100 kHz – 230 MHz vector reflectometer (and, with the external “Sark-110-ULM” 2-port adapter, a limited 2-port VNA) in a 100 × 60 × 14 mm aluminum case the size of a small smartphone — monochrome OLED display (later revisions used 128 × 64 OLED), USB-powered or 800 mAh Li-ion for ~3-hour standalone operation, OSL calibration with stored cal-kit characterization, PC software (Sark Plots) for trace overlay and S1P export, pre-NanoVNA price of $379-$499 depending on revision.
In its 2014-2019 window the Sark-110 was the right instrument for vector measurement in a pocket form factor — actual R+jX with phase, Smith-chart display, S1P export — at $400. It did things the contemporaneous MFJ-259D fundamentally could not (phase, Smith chart, complex vector math, file export) at price and size points the contemporaneous RigExperts could not match. Varela ceased production circa 2020 — the NanoVNA-H V1 launched at $50 in 2019 and the Sark-110’s category collapsed.
What survives in 2026 is a used market of $200-400 depending on condition and whether the 2-port adapter is included. The instrument is well-engineered (aluminum chassis, panel-mount SMA, stable firmware) and surviving units are usually in good shape. No manufacturer support, no firmware updates, PC software unmaintained but functional on Windows 7-11. A Sark-110 bought today is a permanently-frozen-feature-set instrument.
For: unmatched pocket form factor (smaller than a NanoVNA-H V3, dramatically smaller than AA-230 Zoom), industrial-grade build, excellent cal retention across power cycles. Against: NanoVNA-H V3 does everything plus more at a fifth the used-market price; firmware will never improve; the 2-port adapter is rare on the used market; no source for replacement SMA panel-mounts when they fail. The Sark-110 is a museum-piece purchase for collectors of early-era pocket vector instruments, not a recommended primary instrument. The recommended instrument at that performance tier is the NanoVNA-H V3 or LiteVNA-64 (Vol 24).
6. Comet CAA-500 — 1.8-500 MHz amateur analyzer
Japanese vendor Comet (Comet Antenna Co., Saitama) is best known to US hams for HF mobile antennas and CMC-200 mobile mounts; the CAA-500 is their entry in the analyzer market and is rare in US ham shops outside specialty importers. A 1.8-500 MHz handheld with a 320 × 240 color TFT display, USB-to-PC interface, internal NiMH battery, and a distinctive dual-meter analog needle display alongside the digital TFT (a deliberate design choice — Japanese amateur convention favors analog needle for at-a-glance SWR-nulling). Price ~¥45-55k in Japan (≈$300-380 mid-2026 USD), or $450-550 landed through US importers.
The CAA-500 MarkII (~2022) adds Bluetooth Low Energy to a companion Android app — sweeps downloaded to phone, PDF report generation. Useful for field work; app is Japanese-language-first with English menus but Japanese help text and PDF reports.
Comparison to RigExpert: CAA-500 covers slightly wider VHF/UHF (to 500 MHz vs AA-230 Zoom’s 230) but doesn’t reach the AA-600 (600 MHz) or AA-2000 Zoom (2 GHz). Build quality comparable; Comet’s industrial design (analog meter, chrome bezel, rotary front-panel knob) reflects Japanese ham aesthetics. The dual-display approach is a genuine feature for fast SWR-nulling — analog needle swing rate gives intuitive feedback a digital readout cannot.
In US deployments uncommon — vendor support via Japanese distributors only, firmware updates from Comet’s Japanese website, replacement parts from Japan. Functionally similar to a RigExpert AA-600 with worse documentation availability outside Japan but a different ergonomic flavor. For US operators the RigExpert is the easier purchase; for those who value the Comet industrial design heritage or live in Japan, the CAA-500 is a defensible alternative. Used market: $200-300 for a clean MarkI, $350-500 for a MarkII with Bluetooth. Measurement performance comparable to equivalent RigExpert at HF/VHF — both are calibration-kit-limited at that level.
7. Full-instrument VNAs — Keysight / R&S / Copper Mountain
The instruments in this section are commercial-grade vector network analyzers — true 2-port (often 4-port) S-parameter measurement systems with dynamic range, phase accuracy, temperature stability, and absolute-power calibration that are categorically beyond what any NanoVNA-class instrument provides. Prices range from $4,000 for the entry-level Copper Mountain USB-tethered units to $50,000+ for premium handheld FieldFox configurations and benchtop Keysight E5071C ENA-series units. None of these are amateur purchases at full price; all of them appear on the used market at 10-30% of new price (the HP 8753ES being the canonical example, covered in §9), and at that price point they become genuinely accessible to serious amateur operators with measurement-heavy workflows.
Keysight FieldFox handheld series
Keysight’s FieldFox is the handheld field-portable VNA line, descended from the Agilent N9912/N9913/N9914 family launched late 2000s and continually refreshed. The 2026 lineup includes the N9914A (30 kHz to 6.5 GHz), N9923A (2 MHz to 6 GHz, lower-end), and N9952A (5 kHz to 50 GHz, premium microwave), with options for spectrum analyzer, cable-and-antenna-test mode, and signal generator bundled into a single battery-powered instrument.
Defining characteristics: 120-130 dB dynamic range at 1 Hz IF (falls to ~100 dB at 1 kHz IF for faster sweeps), 0.05° phase accuracy with Keysight 85052D or 85033E cal kit, calibrated absolute power to ±0.5 dB across full range, 3-4 hours per battery with hot-swappable Li-ion packs, daylight-readable 8” LCD, MIL-PRF-28800F ruggedization (drop, vibration, -10 to +55 °C), ~3.0 kg without batteries. Prices new: $15k for N9914A basic, $25-35k with SA + sig-gen options, $50k+ for the N9952A 50 GHz unit.
The FieldFox is the standard for defense, aerospace, telecom field maintenance, and broadcast engineering — situations where the instrument must operate outdoors for hours, take abuse, and produce calibration-traceable measurements for compliance documentation. For amateur use, overkill at new price but appears on the used market at $8-15k for previous-generation N9912A/N9913A units, which puts it in reach for serious enthusiasts who want a do-anything-in-the-field VNA.
Rohde & Schwarz ZNL benchtop series
R&S’s ZNL series (ZNL-3, ZNL-6, ZNL-14, ZNL-20) is the company’s entry-level benchtop VNA line (entry-level being a R&S term — the ZNB and ZNA tiers are mid and premium). Frequency ranges: 5 kHz to 3 GHz (ZNL-3), 5 kHz to 6 GHz (ZNL-6), 14 GHz, 20 GHz. All 2-port S-parameter analyzers with optional combined VNA + spectrum analyzer + signal generator (the FPL1000 platform).
Specifications: 130 dB dynamic range (IF-BW dependent), 0.03° phase accuracy with R&S cal kit, calibrated absolute power, USB/LAN/GPIB control, 12.1” touchscreen, ~7 kg benchtop. Prices new: $8k for ZNL-3 base, $15-25k for ZNL-6 with options, $30k+ for the microwave configurations. R&S positions the ZNL as premium-amateur-to-commercial bench — too expensive for casual hobby use, accessible to research labs and small RF businesses. Used/refurb ZNL-3 units appear at $4-6k when government or telecom labs cycle them out.
The ZNL competes head-to-head with the Keysight ENA-L series; choice between them is usually driven by existing institutional vendor relationships (lab that already has R&S spectrum analyzers buys R&S VNAs; lab with Keysight buys Keysight).
Copper Mountain USB-tethered VNAs
Copper Mountain Technologies (Indianapolis, IN) makes USB-controlled VNAs explicitly marketed as value alternatives to Keysight/R&S benchtops. The S5048 (300 kHz – 4.8 GHz, 2-port), SC5065 (9 kHz – 6.5 GHz, 2-port), and S7530 (300 kHz – 3 GHz, 4-port) are the amateur-accessible tier at $4k / $6-8k / $10-12k new. Higher Cobalt and CobaltFX series extend to 67 GHz at $30-100k new and are not amateur-accessible.
The Copper Mountain instruments are USB-controlled — no display, no battery, no standalone operation. The unit is a sealed RF box with USB and BNC/N/SMA connectors; control and display happen via Windows or Linux PC software (full S-parameter capability, time-domain, Smith chart, trace math, regularly updated). The PC-tethered model trades portability for cost. An S5048 at $4k delivers 130 dB dynamic range and 0.05° phase accuracy across 0-4.8 GHz, competitive with the Keysight FieldFox N9914A at 4× the price.
The SC5065 at $6-8k is arguably the sweet spot for the operator who has outgrown the NanoVNA but cannot justify FieldFox or ZNL prices — the “premium amateur” VNA tier in 2026, used by independent RF consultants, small antenna manufacturers, and academic research labs as their primary instrument.
Keysight ENA / PNA benchtop
The Keysight E5063A (100 kHz to 8.5/14/18 GHz, 2-port) and E5071C (100 kHz to 20 GHz, 4-port option) ENA series are the workhorse benchtop VNAs of Keysight’s RF lab portfolio. Prices new: $15-25k for an E5063A, $25-40k for an E5071C. Specifications match R&S ZNL — 130 dB dynamic range, 0.03° phase accuracy, calibrated absolute power, 12” touchscreen, LAN/GPIB/USB. Differentiators are Keysight’s broader cal-kit library (every standard RF connector has a Keysight cal kit), longer software lifecycle, and institutional inertia.
The PNA series (N5224B, N5225B, etc.) is the Keysight premium tier — to 110 GHz, 145 dB dynamic range, sub-0.01° phase accuracy, $50k-$500k new. Not amateur instruments at any price; appears used only when major aerospace or telecom labs cycle them out, where they reach $20-100k and are still above amateur reach.
HP 8753ES — the legacy benchtop king
The Hewlett-Packard (later Agilent, now Keysight) 8753ES is the canonical 1990s-2000s benchtop VNA, manufactured 1995-2005 and deployed in essentially every RF lab in the world during that window. Specs: 30 kHz – 6 GHz (8753ES; the 8753D and 8753C cover 30 kHz – 3 GHz; 8753ET is transmission-only), 110 dB dynamic range, 0.05° phase accuracy, GPIB-controllable, 7” CRT display (later units LCD), ~425 × 220 × 480 mm at 18 kg. New price in 1995 was $30-50k. Today eBay typically has 10-20 units listed, $1,500 (as-is no display parts unit) to $6,000 (fully working with cal kit and recent cert), typical clean working unit $2,500-4,000.
The 8753ES is the king of the used VNA market for a specific reason: the instrument is genuinely excellent (performance comparable to a 2010s Keysight E5063A at 5 % the price), HP service documentation is exhaustive and available online (HPmemoryproject.org), the GPIB protocol is well-documented and supported by every RF measurement software package (LabVIEW, Python PyVISA, MATLAB), and failure modes are well-understood after 25+ years of community experience.
What the 8753ES gives an operator that the NanoVNA does not: 110 dB dynamic range (vs 50-80 dB), 0.05° phase accuracy (vs 0.5-1°), calibrated absolute power, oven-stabilized 10 MHz reference (vs TCXO drift), GPIB/LAN automation, and a cal-kit ecosystem with 85033E, 85052D, and dozens of other standards with full characterization data. Downsides: 18 kg not-portable, 25-year-old CRT failures in early units, source PLL aging, and the cal-kit requirement (without an included 85033D or 85033E, budget $1,500-3,000 additional — see §10). For an amateur operator with bench space, sustained filter/amplifier/BALUN workflow, and willingness to deal with 25-year-old test equipment, the HP 8753ES at $2,500-4,000 with a cal kit is the single best value in the used-VNA market.
Summary — what these give you that the NanoVNA doesn’t
In dense form: dynamic range 110-130 dB vs 50-80 dB, phase accuracy under 0.1° vs 0.5-2°, calibrated absolute power to ±0.5 dB, oven-stabilized reference for temperature stability, NIST-traceable cal history, GPIB/LAN automation for production workflows, cal-kit ecosystem characterized to 50+ GHz vs stock kits valid to 1-3 GHz. None of these are required for typical amateur antenna work; all are required for serious RF engineering, and a commercial VNA is the only way to get them.
8. When to step up from a NanoVNA
The following decision matrix covers the most common measurement scenarios and the right instrument tier for each. The “stay” column means the NanoVNA-class instrument from Vol 24 is adequate; the “step up” columns indicate when to move to a mid-tier or bench-tier instrument.
| Scenario | NanoVNA | Mid-tier | Bench VNA |
|---|---|---|---|
| SWR sweep of a single antenna 1.8-30 MHz | yes | yes (RigExpert AA-230 Zoom adds ergonomics) | overkill |
| SWR sweep of a single antenna VHF/UHF | yes | yes (RigExpert AA-600 adds ergonomics) | overkill |
| Tuning a multi-band BALUN across 1.8-30 MHz | yes | not better than NanoVNA | yes if NIST-traceable required |
| Measuring 1-port impedance for matching network design | yes | RigExpert standalone faster on bench | yes for production work |
| Measuring filter shape factor at -20 to -40 dB | yes | not 2-port capable | yes (better than NanoVNA at depth) |
| Measuring filter shape factor at -60 to -80 dB | no — dynamic range insufficient | not 2-port capable | yes — bench VNA mandatory |
| Measuring filter shape factor below -100 dB | no | no | bench VNA + signal generator + spectrum analyzer |
| Measuring BALUN common-mode rejection | yes (with proper test fixture, see Vol 16) | not 2-port capable | yes (better dynamic range helps) |
| Measuring amplifier S21 gain | yes | not 2-port capable | yes (calibrated input power matters) |
| Measuring LNA noise figure | no — not a VNA measurement | no | no — needs spectrum analyzer + noise source (Vol 27) |
| Measuring amplifier IMD | no — not a VNA measurement | no | no — needs spectrum analyzer + 2-tone generator (Vol 27) |
| Time-domain reflectometry for coax fault-finding | yes | RigExpert standalone faster in field | yes but overkill |
| Calibrated EIRP measurement of an antenna | no — uncalibrated power | no | yes via VNA + reference antenna + calibrated SA (Vol 27) |
| Production QC of antennas with go/no-go limits | usable but awkward | RigExpert / Sark-110 workflow better | yes for high-volume work |
| Compliance documentation for FCC certification | no — not NIST-traceable | no | yes — commercial VNA + cert lab cal |
Most amateur antenna work is in the top half of the matrix where NanoVNA-class is fully adequate. Forcing functions for bench VNA purchase are deep stopband measurement (below -60 dB filter rejection), calibrated absolute power (EIRP, regulatory compliance), and any measurement going on a legal or compliance document. The mid-tier RigExpert / Sark-110 is rarely more accurate than the NanoVNA for measurements where both are technically adequate — differentiation is workflow ergonomics (saved sweeps, daylight screen, faster retuning), justifying the cost only for production-rate work. The realistic amateur-accessible bench option is a used HP 8753ES at $2,500-4,000 with cal kit, or a used Keysight ENA E5063A at $5,000-8,000; new $15k+ instruments are rarely justifiable for amateur use.
9. Used / refurb market — what to buy on eBay
The used commercial VNA market is one of the more functional segments of eBay — units appear regularly, prices are reasonably stable, and a small number of reputable dealers operate consistently enough to provide warranties and calibration services. The following sections cover the buyer’s-guide considerations specific to each major instrument class.
Reputable sellers
A short list of US-based dealers with consistent track records on used RF test equipment, as of mid-2026:
- TestEquity (Moorpark, CA) — large dealer of refurb test equipment, sells with 30-90 day warranty depending on item, calibration certificates available at additional cost. Higher prices than eBay individuals but lower risk.
- Brite Bear (Saginaw, MI) — specializes in HP/Agilent/Keysight test equipment, run by ex-HP service techs, includes recent calibration with most sales, prices typically 15-30% above eBay individuals but with verified working condition.
- NetCom Test Equipment (Naples, FL) — mid-size dealer, broader inventory across HP/Tek/Fluke, 90-day warranty standard, calibration available.
- Geneva Test Equipment (Mountain View, CA) — Silicon Valley dealer, frequently has telecom-cycle-out instruments, good source for Copper Mountain and HP 8753 family.
- eBay with warranty + 90-day return — individual sellers who offer warranty and accept returns are typically legitimate; sellers who require “as-is no returns” should be approached with caution. The 5-star feedback rating with 100+ reviews on test-equipment sales is the relevant signal.
- Avoid — auction sites without return policies, sellers based outside the US who require international shipping (customs delays and damaged shipments are common), and “estate sale” listings without operational verification (“powers on” is not equivalent to “works”).
Specific failure modes per instrument family
HP 8753 family — youngest units are 20+ years old in 2026. (1) Source PLL aging — YIG oscillator drift, eventually losing lock on certain frequency segments. Symptoms: spurs in output, “source unleveled” error at certain bands. Repair: YIG replacement, $500-1500. Verify before purchase: ask for full-frequency-range S11 sweep of an open standard; spurs in the trace are the symptom. (2) GPIB drum-and-flop — known capacitor failure on the HP-IB interface card. Symptoms: instrument works standalone but won’t respond to GPIB commands, or responds intermittently. Repair: cap replacement, $50 of parts + 2 hours. Verify: ask for demonstration of GPIB-to-PC remote sweep. (3) Battery-backup SRAM dying — the lithium backup battery has a ~25 year lifespan; instrument boots to “no calibration available” or “memory error.” Repair: battery replacement + SRAM re-init, $30 parts + 1 hour. Verify: ask whether calibration persists across power cycles. (4) CRT failure in pre-LCD units (8753A/B/C/D); LCD replacement kits from HPMemoryProject and similar are $400-800.
Keysight FieldFox — primarily field-use damage. (1) NiMH battery pack degradation on 2010-era units; replacement Keysight packs $200-400, third-party rebuilds $100-200. (2) Front-panel BNC wear from heavy field use, $50-100 + 1 hour. (3) Touchscreen calibration drift — re-cal via service menu, no cost. (4) MMC card slot wear from repeated insertions, $100-200 + 2-3 hours.
R&S ZNL — relatively young (post-2015). Front-panel encoder wear ($20-50 user-replaceable), cooling-fan failure after 5-10 years bench use ($50 + 1 hour), touchscreen failure requiring full assembly replacement at $1,500-2,500 through R&S (avoid units with touchscreen issues unless dealer is providing repair).
Copper Mountain — young, USB-tethered, minimal failure modes. USB connector wear on heavy-use units (PCB rework, rarely worth it), internal calibration EEPROM drift over decades requiring factory re-cal at ~$500-1500.
Calibration history matters
A bench VNA without recent calibration certificate is a probability distribution of accuracies, not a guaranteed accuracy. Measurements remain useful for relative comparisons (this antenna’s SWR is 1.3 vs this one’s 1.8), but absolute accuracy and traceability are unknowns. For a serious purchase, ask for: (1) date of last full calibration (within 1-3 years ideal, within 5 acceptable, beyond 10 suspect); (2) calibrating laboratory (factory cal by Keysight/R&S/Anritsu is gold; A2LA-accredited independent is silver; unaccredited “we have a cal kit” shop is bronze); (3) the calibration certificate itself (a one-page PDF of measured-vs-spec at calibration frequencies; absence indicates cal never performed or never documented); (4) cal-kit serial numbers used during the cal (mismatch between cert and the kit actually included is a red flag).
Re-calibration costs in 2026: Keysight factory cal of an 8753ES is $1,500-2,500 plus shipping. R&S factory cal of a ZNL is $2,000-3,500. Independent A2LA-accredited cal is typically $500-1,500. For amateur use, independent lab is usually the right balance; for compliance-document use, factory is mandatory.
Cal-kit-is-the-instrument
The most consistently underestimated cost in used-VNA purchase. A working HP 8753ES at $3,000 with no cal kit is a $3,000 paperweight until a cal kit is purchased. Cheapest credible cal kit for the 8753 is the HP 85033D ($800-1500 used) or 85033E ($1,500-2,500 used); a Pasternack PE17 series at $400-600 new is characterized to 18 GHz (over-engineered for the 8753’s 6 GHz top but not in a way that hurts). Budget cal-kit purchase as a mandatory line item on any used-VNA buy — $3,000 8753ES + $1,500 cal kit is the real entry price, call it $4,500 for the working setup.
eBay red flags
Listing phrases that should trigger scrutiny: “Powers on but display is dim/dead/has lines” (display repair often uneconomical; deduct $500-1500); “Works as far as I can tell, no further testing” (translates to “no instruments to verify”; assume non-working); “As-is no returns” combined with no verification photos/videos (highest-risk category); “No power cord / manuals / accessories” combined with “no calibration kit” (may not be cost-effective once accessories sourced); “Recently calibrated” without provided certificate (ask for the cert); “International seller” (customs delays of 3-6 weeks and shipping damage common; savings usually don’t offset risk for used test equipment).
Used-market price ranges mid-2026 are summarized in the §11 commercial-buys tables below; instruments labeled “(used)” in those tables are the same instruments covered above with the failure-mode and verification notes from this section.
10. Calibration kits — the cost of accurate measurement
VNA measurement accuracy is fundamentally limited by the accuracy of the calibration standards. The instrument computes an error correction matrix from measurements of “known” standards — open, short, 50 Ω load, through (OSL+T for 2-port SOLT). The math assumes each standard is ideal (open is perfect, short is perfect, load is exactly 50.000+j0 Ω, through is lossless zero-length), measures each, attributes any deviation to the instrument’s systematic error, and builds the correction matrix.
Real standards are not ideal — open has fringing capacitance at the connector face, short has series inductance from connector geometry, load is 50.0 ±0.5 Ω with small reactive component, through has insertion loss and phase delay. Accuracy depends on whether the error model uses ideal values for the standards (the simplest case, stock NanoVNA cal kits) or characterized values (Keysight 85033E and similar, where the manufacturer measured actual S-parameters of each standard at every frequency of interest and provides the data as a file the instrument loads).
A NanoVNA with a $20 stock kit and ideal-model assumption is accurate to ±0.5-1.0 dB and ±2-5° at HF, degrading to ±2-3 dB and ±5-15° at UHF. The same NanoVNA with a $3,000 Keysight 85033E and characterization file is accurate to ±0.1-0.2 dB and ±0.5-1.5° across its full range. The instrument is identical; the cal kit moves the accuracy by an order of magnitude. The implication: a $60 NanoVNA + $3,000 cal kit approaches the measurement quality of a $30,000 Keysight benchtop on common antenna work. The bench instrument has other advantages the NanoVNA cannot match (dynamic range, automation, temperature stability), but for “measure this antenna’s R+X+SWR vs frequency accurately,” the limiting factor is the cal kit, not the instrument.
| Tier | Example | Price (mid-2026 USD) | Useful to | Characterization | Notes |
|---|---|---|---|---|---|
| 1 — Stock | NanoVNA bundled (Open/Short/50Ω/M-F) | $20-40 | ~1 GHz | ”ideal” model, no measured data | OK for 1-port HF; degrades at UHF |
| 2 — Improved consumer | Pasternack PE17 series | $300-600 | 18 GHz | S-parameter file per standard | Best value tier; the upgrade for serious NanoVNA work |
| 3 — Commercial mid-tier | Mini-Circuits CAL-LK-1 | $800 | 6 GHz | Factory characterized S2P data | One-stop SMA to 6 GHz |
| 4 — Lab-grade | Keysight 85033E (3.5 mm), Anritsu 3650A (SMA) | $2,000-3,500 | 9 GHz | NIST-traceable factory characterization | Standard for HP 8753ES and Keysight ENA |
| 5 — Microwave metrology | Keysight 85052D (3.5 mm precision) | $5,000-8,000 | 26.5 GHz | NIST-traceable, certified per-standard data | For mm-wave; mandatory for microwave compliance |
The Pasternack PE17 is the sweet spot for amateur work that has outgrown the stock NanoVNA kit — $400 for a 4-piece (open, short, 50 Ω load, through) characterized to 18 GHz (over-engineered for NanoVNA but not in a way that hurts). The Keysight 85033E is the cal kit for an HP 8753ES purchase; the two together are the canonical used-bench-VNA setup, and the 85033E’s NIST-traceable characterization is what enables compliance-grade measurements. Used 85033E kits on eBay range $1,500 (older characterization, may need re-cert) to $3,000 (recent factory cal with cert). The Keysight 85052D is precision 3.5 mm to 26.5 GHz at $5-8k used — for microwave amateur work and Wi-Fi-band measurement at the high edge of 2.4-2.5 GHz; below 6 GHz the 85033E suffices.
Connector wear: cal-kit connectors are precision SMA or 3.5 mm parts. Each connect-disconnect wears the connector slightly, and after ~500 cycles the standard is out of tolerance and S-parameters no longer match the characterization file. Pasternack PE17 standards are $150-200 each to replace; Keysight 85033E standards require return to Keysight for re-characterization at $500-1500 each. Lesson: do not use cal-kit standards as everyday adapters. Keep them in their case, use only for calibration, and budget replacement on a 5-10 year cycle for heavy users.
11. Commercial buys
Sorted by price tier (USD, mid-2026, new prices for current production, used prices noted where applicable):
Budget tier ($60 – $500)
| Instrument | Price | Coverage | Notes |
|---|---|---|---|
| NanoVNA-H V3 | $60-90 | 50 kHz – 1.5 GHz | The reference Vol 24 instrument |
| NanoVNA-F V3 | $130-180 | 50 kHz – 1.5 GHz | Larger screen, same RF as -H V3 |
| LiteVNA-64 | $200-300 | 50 kHz – 6.3 GHz | 4” touch-screen, 2-port |
| RigExpert AA-35 / AA-Stick Pro | $300 | 60 kHz – 35 MHz / 0.1-1300 MHz | HF-only standalone / USB no-display |
| RigExpert AA-55 Zoom | $370 | 60 kHz – 55 MHz | HF+ standalone |
| RigExpert AA-230 Zoom | $430 | 100 kHz – 230 MHz | HF + low-VHF (volume leader) |
| MFJ-259D / 269D (used) | $200-425 | 1.8 – 230/470 MHz | Used only; MFJ shut down 2023 |
| Sark-110 (used) | $200-400 | 100 kHz – 230 MHz | Used only; discontinued |
Mid tier ($500 – $2,000)
| Instrument | Price | Coverage | Notes |
|---|---|---|---|
| RigExpert AA-600 | $590 | 100 kHz – 600 MHz | Adds full UHF |
| RigExpert AA-2000 Zoom | $900 | 100 kHz – 2 GHz | Premium standalone amateur |
| Comet CAA-500 / MarkII (US import) | $450-750 | 1.8 – 500 MHz | Japanese alternative; rare US |
| HP 8753ES (used, no cal kit) | $1,500-3,000 | 30 kHz – 6 GHz | Add $1,500 for cal kit |
Premium tier ($2,000 – $50,000)
| Instrument | Price | Coverage | Notes |
|---|---|---|---|
| HP 8753ES (used, with cal kit) | $3,000-4,500 | 30 kHz – 6 GHz | Canonical used-bench-VNA setup |
| Copper Mountain S5048 (new) | $4,000 | 300 kHz – 4.8 GHz | USB-tethered 2-port |
| Keysight E5063A (used) | $4,000-8,000 | 100 kHz – 8.5 GHz | Used benchtop ENA |
| R&S ZNL-3 (refurb / new) | $4,000-6,000 / $8,000 | 5 kHz – 3 GHz | Refurb or new benchtop |
| Copper Mountain SC5065 (new) | $6,000-8,000 | 9 kHz – 6.5 GHz | Premium-amateur sweet spot |
| Keysight FieldFox N9912A / N9914A (used) | $5,000-18,000 | 30 kHz – 4/6.5 GHz | Used handheld tier |
| R&S ZNL-6 (refurb) | $7,000-11,000 | 5 kHz – 6 GHz | Refurb benchtop |
| Keysight E5071C (used) | $8,000-18,000 | 100 kHz – 20 GHz | 4-port option available |
| Keysight FieldFox N9914A (new) | $15,000-25,000 | 30 kHz – 6.5 GHz | With SA + sig-gen options |
| Keysight E5063A / R&S ZNL-6 (new) | $15,000-25,000 | 100 kHz – 8.5 GHz / 6 GHz | New benchtop ENA / ZNL |
| Keysight E5071C (new) | $25,000-40,000 | 100 kHz – 20 GHz | New 4-port ENA |
| Keysight FieldFox N9952A | $50,000+ | 5 kHz – 50 GHz | Microwave handheld |
Recommended purchase paths
Recommended progression for the operator starting from zero: (1) NanoVNA-H V3 + stock cal kit at $60-90 covers 95 % of amateur antenna work; (2) upgrade to Pasternack PE17 cal kit at $400-600 — same NanoVNA, accuracy matching a $2k AA-2000 Zoom at HF/VHF and improving toward UHF; (3) add RigExpert AA-230 Zoom at $430 only if field-portable ergonomics genuinely matter; for bench work, skip and stay on NanoVNA; (4) step to bench VNA via used HP 8753ES + 85033E cal kit at $3,500-4,500 — the right step up for sustained 2-port work (filters, BALUNs, amplifiers); (5) step to new bench via Copper Mountain SC5065 at $6-8k — new equipment with warranty, USB automation, full Keysight/R&S-class performance at half the price; (6) premium tier (Keysight ENA / R&S ZNL / FieldFox) at $15k+ only for workflows that justify it (RF consulting, small RF manufacturing, sustained compliance work).
For most amateur readers, the right purchase in 2026 is paths 1+2 — NanoVNA-H V3 plus Pasternack cal kit, $500 total, covering nearly all antenna work in Vols 6-19 with respectable accuracy. Path 4 is the right next step for operators who outgrow that; path 6 is rarely justifiable for amateur use.
12. Common gotchas and myths
“An analyzer is good enough for everything.” True for single-port antenna work where R+X+SWR vs frequency is the question; false for filter characterization, BALUN insertion loss, amplifier gain, or anything else that needs through measurement. The 1-port analyzer is right for 1-port questions; a 2-port VNA is right for 2-port questions, with no software workaround. The NanoVNA gets the 2-port upgrade for free; the RigExpert and MFJ analyzers do not.
“A used HP 8753 is a bargain.” Conditional on the unit’s specific condition. A working 8753ES at $3,000 with cal kit and recent cert is genuinely a bargain — equivalent measurement performance to a $25k new instrument. A non-working 8753ES at $1,500 with “powers on but doesn’t sweep” is not — diagnosing and repairing 25-year-old test equipment can exceed the instrument’s value. Three failure modes to verify before purchase: source PLL aging (request full-range S11 sweep of an open showing no spurs), GPIB drum-and-flop (request PC remote-control demonstration), battery-backup SRAM failure causing “no cal” boot loop (request demonstration that calibration persists across power cycles). Without those three verified, assume non-working and price at $1,500 or less.
“RigExpert is more accurate than NanoVNA.” False at HF where both are calibration-kit-limited (both achieve ~±1 dB and ±2-3° with stock kits, ±0.3 dB and ±1° with Pasternack-tier). At VHF/UHF the RigExpert’s discrete resistive bridge is marginally better than the NanoVNA’s broadband mixer (1-2 dB and 2-5° delta), meaningful for precision metrology, not meaningful for amateur antenna work. RigExpert wins on ergonomics, screen, and battery life; NanoVNA wins on 2-port capability and price. Raw measurement accuracy is not the differentiator.
“I’ll buy a $30k VNA used for $3k.” Realistic for HP 8753ES specifically (20+ years of used supply has driven prices to 10% of new); less realistic for newer commercial VNAs (Keysight ENA E5063A/E5071C floor is closer to 30-50% of new — less supply, more features newer instruments still don’t match, ongoing Keysight service network adding value). Budget $1-3k for re-cal at an A2LA-accredited lab regardless of what is purchased, unless the unit comes with a recent factory cal cert.
“My calibration kit lasts forever.” False. Cal-kit connectors are precision parts with mechanical wear. The female SMA on a working standard is good for ~500 connect cycles before center-pin alignment drifts and S-parameters no longer match the characterization file — past that the instrument believes its cal is valid when it actually isn’t. Pasternack PE17 standards $150-200 to replace; Keysight 85033E standards require Keysight re-characterization at $500-1500 each. Do not use cal-kit standards as everyday adapters.
“The FieldFox is just a portable Keysight benchtop.” Partial truth — same RF technology family, consistent UI. Differences: FieldFox dynamic range 110-120 dB vs bench E5071C’s 130 dB, phase accuracy 0.1° vs 0.03°, narrower IF bandwidth options, smaller touchscreen. FieldFox wins on battery, daylight LCD, MIL-spec ruggedization, hot-swap packs. Complementary, not redundant — FieldFox for field work where the bench cannot go, bench for any measurement that doesn’t have to leave the lab.
“Buying a VNA without a cal kit is fine — I’ll add one later.” Technically true but almost always under-budgeted. $3k HP 8753ES without cal kit is a $4,500 working setup once an 85033E or PE17 is added. Always include cal-kit purchase as a mandatory line item; the all-in price is the relevant number.
“NanoVNA dynamic range is good enough.” True for 95% of antenna work; false for anything requiring -60 dB and below relative to reference (filter stopband, IMD, noise floor). NanoVNA-H V3 floor is ~-70 dB on S21 at HF, degrading to -55 dB at 1.5 GHz. Below those floors, a bench VNA’s 130 dB dynamic range is the technical reason for the upgrade.
13. Resources
RigExpert — Main site: https://rigexpert.com. AA-230 Zoom: https://rigexpert.com/products/antenna-analyzers/aa-230-zoom/. AA-2000 Zoom: https://rigexpert.com/products/antenna-analyzers/aa-2000-zoom/. AA-Stick Pro: https://rigexpert.com/products/antenna-analyzers/stick-pro/. AntScope2 software: https://rigexpert.com/files/software/antscope2/.
Keysight FieldFox / ENA — FieldFox product family + app notes: https://www.keysight.com/us/en/products/network-analyzers/fieldfox-handheld-rf-microwave-analyzers.html. E5063A ENA-L: https://www.keysight.com/us/en/product/E5063A/. E5071C ENA: https://www.keysight.com/us/en/product/E5071C/. Calibration-kit overview: https://www.keysight.com/us/en/cmp/2020/calibration-kits.html.
HP 8753 family — HP Memory Project (service manuals): https://hpmemoryproject.org/. Used-HP-VNA community: https://groups.io/g/HP-Agilent-Keysight-equipment. 8753ES service manual mirror: https://archive.org/details/manual_hp8753es.
Pasternack / cal kits — PE17 series: https://www.pasternack.com/calibration-kits-category.aspx. Mini-Circuits CAL-LK-1: https://www.minicircuits.com/pdfs/CAL-LK-1.pdf. Anritsu 3650A: https://www.anritsu.com/en-us/test-measurement/products/3650a.
R&S ZNL — Product overview + datasheets + app notes: https://www.rohde-schwarz.com/us/products/test-and-measurement/vector-network-analyzers/rs-znl-vector-network-analyzer_63493-411904.html.
Copper Mountain — Main: https://coppermountaintech.com. S5048: https://coppermountaintech.com/vna/s5048/. SC5065: https://coppermountaintech.com/vna/sc5065/. S7530: https://coppermountaintech.com/vna/s7530/.
US-based refurb dealers — TestEquity: https://www.testequity.com. Brite Bear: https://www.britebear.com. NetCom: https://www.netcomtest.com. Geneva Test: https://www.genevatest.com.
Comet CAA-500 — Comet Antenna Co. (Japanese): https://www.comet-ant.co.jp. US distributor (Universal Radio): https://www.universal-radio.com.
Sark-110 — Manufacturer site (intermittent): http://www.sark110.com. User group: https://groups.io/g/sark110.
Cross-references within this deep dive
- Vol 4 (Antenna theory) — Smith-chart fundamentals
- Vol 5 (Transmission lines & feedlines) — coax types, velocity factors used in TDR
- Vol 16 (BALUNs and UNUNs) — 2-port measurement topology for BALUN characterization, common-mode rejection test fixtures
- Vol 17 (Antenna tuners) — matching-network measurement workflow
- Vol 24 (NanoVNA Deep Dive) — the canonical low-cost vector instrument; this volume is the “everything else” companion
- Vol 26 (RF power, SWR & field-strength) — wattmeters, dummy loads, signal generators (the non-VNA measurement gear)
- Vol 27 (Spectrum analyzers) — when a spectrum analyzer is the right tool (IMD, noise figure, EIRP) rather than a VNA
- Vol 28 (Antenna modeling software) — NEC-2/EZNEC predicted patterns vs measured-on-instrument validation