Smart water meter electronics for New Zealand may carry a 22 nanohenry inductor in a radio match. In the Walsin Technology (Walsin) 0402 export we found 22 rows in 8 series, 21 sharing just two data sets (Q 25 and Q 8), one a ferrite bead, none on our shelf.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the Walsin inductor export of 5,410 real rows (the 5,411th is a test row we exclude) and a ready-stock list dated 23 September 2026. This post is for a design or procurement engineer at a New Zealand meter maker, utility contractor or telemetry developer who has a radio-matching inductor on a bill of materials and wants a second source in small lots from Hong Kong. Every Walsin part number is real, every count is ours, and the news statement names its source and the day we fetched it, 2 November 2026.
What does Christchurch’s smart water meter rollout mean for an electronics buyer?
It means a metering programme that is under way now, not a plan. SmartCitiesWorld reported on 28 January 2026 that Christchurch has started installing smart water meters in parts of the city and Banks Peninsula, prioritising areas that currently have none, and that the programme treats opting out as not an option because it regards the rollout as critical for a resilient and efficient network.
The page we read on 2 November 2026 sits behind a registration wall after its introduction, so we cite only that introduction: it gives no meter count, timeline, budget or technology, and it names no component or supplier. We therefore draw no link between it and any part number. Our view, labelled as ours: a metering rollout is a long, repeated build of small battery-powered boards, and a radio-matching inductor is one of the parts that has to be sourced twice. We have no relationship with Christchurch City Council or any meter maker.
Which Walsin rows answer a 22 nanohenry, 0402 line?
Twenty-two rows in eight series, and only two sets of data behind 21 of them. We parsed all 1,001 Walsin 0402 inductor rows listed in nanohenries and found 22 at 22 nH: 3 each in WCA, WCI, WLCW, WQCW, WLCM, MCI and MCI Automotive, plus 1 in WQBD. We have not seen this line counted anywhere.
The 12 rows in WCA, WCI, WLCW and WQCW publish identical data: Q of 25, 0.3 ohm and 400 mA. The 9 rows in WLCM, MCI and MCI Automotive publish a different identical set: Q of 8, 0.7 ohm and 300 mA. Our post on Walsin inductor series, how to tell them apart explains the prefixes, and inductors for RF matching networks explains why Q matters in a match.
How do the candidates compare field by field?
Tolerance steps and Q separate them. The table sets six rows against a 22 nH, plus or minus 5%, 0402 line.
| Walsin part | Series, thickness | Tolerance, Q min, SRF as exported | On shelf 23 Sep 2026 | Match / mismatch against a 22 nH, 5%, 0402 line |
|---|---|---|---|---|
WCA1005CP22NJ |
WCA, 0.66 mm | 5%, Q 25, SRF 2.8 | No | Match on value, tolerance and case |
WLCW1005Z0J22NTB |
WLCW, 0.66 mm | 5%, Q 25, SRF 2.8 | No | Match on value, tolerance and case; mismatch on prefix and packing code |
WLCM1005Z0J22NTB |
WLCM, 0.5 mm | 5%, Q 8, SRF 1900 | No | Match on value and tolerance; mismatch on Q, 8 against 25, and 0.16 mm thinner |
MCI1005HQ22NJHBP |
MCI, 0.5 mm | 5%, Q 8, SRF 1900 | No | Match on value and tolerance; mismatch on Q, current 0.3 A and series |
WCA1005CP22NG |
WCA, 0.66 mm | 2%, Q 25, SRF 2.8 | No | Mismatch: tolerance, 2% is tighter than 5% |
WQBD1005K2U700TP |
WQBD, 0.3 mm | 5%, Q 9, SRF 2500, 1.2 ohm | No | Mismatch: a ferrite bead series with a 22 nH label, 150 mA |
If the match needs Q, the first two rows are the ones; if it needs the thin body, the multilayer rows are. Whether Q 25 or Q 8 is acceptable is a design decision that stays with you.
What is wrong with the column that holds self-resonant frequency?
It holds a number with no unit, and the numbers differ by a thousand. In the 0402 nanohenry rows the SRF(min) column reads 2.8 on the Q 25 rows and 1900 on the Q 8 rows; across the 1,001 0402 nanohenry rows the column runs from 1.16 to 12.9 on the WCA, WCI, WLCW and WQCW series and from 550 to 10,000 on the WLCM, MCI and MCI Automotive series.
We read the small numbers as gigahertz and the large ones as megahertz, since a 22 nH part resonating at 2.8 MHz would be absurd, but the export prints neither unit and we hold no inductor datasheet to confirm it. A sort or a filter on that column will mix 2.8 and 1900 as if they were the same unit. Treat SRF as unresolved until Walsin confirms it for the code you intend to order. Our inductor range lists the families. The WQBD row also carries a size label of 0402 against a 0.6 by 0.3 mm body, which is a 0201 footprint.
What does the Hong Kong shelf hold for this line?
None of the 22. As at 23 September 2026 our list holds 1,125 distinct part numbers, 2 of them inductors, WLPH252012M2R2PP and WLPH252012M4R7PP, both 2520 power inductors at 2.2 and 4.7 microhenry, and no 0402 inductor of any family.
A 22 nH inductor is therefore a factory order, requested through the site. The ready stock list is a dated snapshot, never live-synced, and we quote part-number counts, never piece counts. Our post on Walsin passive components in Hong Kong stock explains how to read it.
What will we not tell you about meter radios?
Anything about a frequency, a range or a certification. We hold no datasheet for any Walsin inductor, 0 of the 5,410 rows are backed by one of our 28 sheets, and we searched all 28 sheets for water meter, smart meter and metering and found 0 matches.
We cannot say which of the 22 rows suits a given band, and the export publishes no saturation current for them. We hold no office, entity or stock in New Zealand; our locations are Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation. We give no legal, customs or conformity advice; confirm with your compliance team.
Why do buyers in New Zealand choose Venatech?
Because we show a New Zealand buyer the mismatches as well as the matches, and we can prove the rest: 28 Walsin datasheets held, 451 pages, and one named authorised line. Venatech Limited is an authorised Walsin distributor in Hong Kong; Walsin is our only authorised line, and Stackpole and Viking are lines we supply. We confirm nothing we cannot show.
New Zealand meter and telemetry makers often iterate boards in small lots before a rollout, and a prototype quantity is a normal order for us. For a radio-matching inductor:
- We tell you two rows are not alike. Twenty-one of the 22 rows share only two data sets, and Q is the field that differs, 25 against 8.
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We catch the bead. One of the 22 rows is a ferrite bead series with a 22 nH label, and we mark it a mismatch before it reaches your layout.
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Hong Kong-based service, small lots welcome. A prototype or pilot quantity is a normal order for us, requested through the site.
- Breadth you can count. Our Walsin extracts (00_ALL_MLCC_parts_combined.xlsx, Walsin_Inductor_ALL.xlsx, Walsin_MOV_ALL.xlsx, Walsin_DiscCap_ALL.xlsx, Walsin_Antenna_ALL.xlsx and the chip-resistor, thin-film and RF files) hold 359,135 distinct part numbers, and the VenaMatch tool covers 800,000+ crossable parts.
- Honest cross-referencing. Every candidate is shown with each field marked match or mismatch, so you see the gap before you lay out a board.
- Checkable credentials. We are an authorised Walsin Technology distributor in Hong Kong, which you can confirm with Walsin. We hold 28 Walsin datasheets, 451 pages, and send the relevant one on request.
How can Venatech help a New Zealand buyer with a smart-meter radio bill of materials?
By showing the differences instead of hiding them, across 800,000+ crossable parts, in small lots. Venatech Limited is an authorised Walsin distributor in Hong Kong. Walsin is our only authorised line; Stackpole and Viking are lines we supply.
- Cross-reference. Paste your incumbent number into the free cross-reference tool, which decodes 18 manufacturers’ part numbers across 800,000+ crossable parts, and read the Walsin candidates with each field marked match or mismatch.
- BOM check. Upload the whole bill of materials to /bom/, up to 500 part numbers or an Excel or CSV file.
- Ready stock. The ready-stock list is a Hong Kong snapshot dated 23 September 2026, not live.
- Service. Hong Kong-based, small lots, help with cross-referencing by hand when the tool returns no clean candidate, and a quote requested through the site.
Worked example from our own export: a 22 nH, plus or minus 5%, 0402, Q 25 inductor maps to WCA1005CP22NJ or WLCW1005Z0J22NTB, to WLCM1005Z0J22NTB if you accept Q 8, and to nothing on the shelf. Confirm against both datasheets and qualify in your own circuit.
The short version
For a New Zealand meter-electronics buyer, a 22 nH, 0402 line finds 22 Walsin rows in 8 series; 21 share two data sets, Q 25 and Q 8, one is a ferrite bead, the SRF column mixes units, and none is on the Hong Kong shelf.
Paste one radio-match inductor into the free cross-reference tool, or upload the meter board to /bom/, and we will return the Walsin candidates with every difference stated and the stock position named. If your match was tuned with a Q 25 part, how much of the range are you prepared to lose at Q 8?
Sources
Fetched on 2 November 2026 with WebFetch; the pages below are the only sources for news and product statements in this post.
- SmartCitiesWorld, “Christchurch embarks on smart water metering programme”, 28 January 2026, introduction read on 2 November 2026: https://www.smartcitiesworld.net/water/christchurch-embarks-on-smart-water-metering-programme-12406
Frequently asked questions
What did Christchurch announce about smart water meters?
SmartCitiesWorld reported on 28 January 2026 that Christchurch has started installing smart water meters in parts of the city and Banks Peninsula, starting where there are none. We read only the introduction; it names no meter count, technology or supplier.
How many Walsin 0402 inductors are 22 nH?
We counted 22 among 1,001 0402 rows listed in nanohenries, in 8 series: WCA, WCI, WLCW, WQCW, WLCM, MCI, MCI Automotive and WQBD. Twenty-one share two sets of electrical data.
What is the difference between the two data sets?
The WCA, WCI, WLCW and WQCW rows publish Q 25, 0.3 ohm and 400 mA; the WLCM, MCI and MCI Automotive rows publish Q 8, 0.7 ohm and 300 mA. Q is the field most likely to matter in a radio match.
Is a 22 nH inductor on the Hong Kong shelf?
No. As at 23 September 2026 our list holds 2 inductors, both 2520 power parts, and no 0402 inductor. Each candidate is a quote requested through the site. The list is a dated snapshot and is never live-synced.
Why is the SRF column unreliable?
It prints a number with no unit: 2.8 on the Q 25 rows and 1900 on the Q 8 rows. We read them as gigahertz and megahertz but hold no inductor datasheet to confirm it, so confirm with Walsin before you sort on it.
Does Venatech have an office in New Zealand?
No. We hold no office, entity or stock in New Zealand. Venatech Limited is based in Hong Kong with locations in Shenzhen, Singapore and Jiangmen, and Chengdu in preparation. We serve New Zealand buyers from Hong Kong in small lots.