Quick facts
- Caliber
- 7A28(quartz chronograph)
- Jewels
- 15
- Beat rate
- — vphQuartz movement; Mizeni gives a 32,768 Hz crystal, so a mechanical beat rate doesn't apply.
- Hacking / hand-winding
- Yes / —Pending verification
- Water resistance
- —Pending verification
- Crown
- — o’clockExposed crown and an extra pusher on the left side of the case (aBlogtoWatch); exact position not documented.
- Production
- 1982–1992Seiko dates the launch to 1983 as the world's first analog quartz chronograph; collector sources point to production starting in late 1982 and ending around 1991 or 1992. We haven't found a Seiko source for the end, so the decoder treats the window as unverified.
- Modern equivalent
- —Pending verification
Variants
The 7A28 went into many cases. These four are the best known; the variant table lists the ones with their own pages to come.
| Reference | Market | Day wheel | Status |
|---|---|---|---|
| 7A28-7000 | — | — | Pending verification |
| 7A28-7010 | — | — | Pending verification |
| 7A28-7020 | — | — | Pending verification |
| 7A28-7040 | — | — | Pending verification |
Serial decoder
Seiko hasn't documented when 7A28 production ended, so the date finder on this page stays off until we can verify it. The full serial decoder still reads the month and the year's last digit, with low confidence.
Seiko dates the launch to 1983 as the world's first analog quartz chronograph; collector sources point to production starting in late 1982 and ending around 1991 or 1992. We haven't found a Seiko source for the end, so the decoder treats the window as unverified.
Possible production date, not a guaranteed date or an authentication. Production date is not the purchase date.
Full decoder with caliber and case codePrice guide
Prices appear after our first sampling of sold listings in November 2026.
| Condition | Low | Median | High |
|---|---|---|---|
A · Collector | — | — | — |
B · Serviced original | — | — | — |
C · Running, unserviced | — | — | — |
D · Project or suspected franken | — | — | — |
Sampled —, n = —, eBay sold listings viewed manually.
Checks before you buy
With a quartz chronograph, test every function and look inside the battery compartment before anything else.
Reference and market Read the case back first, then match the dial and bracelet to that reference and market.
A dial from another market or reference.
Sources: Collector guide. Our own photo comes with our first shoot.
Dial printing Clean printing with the small edge text in place.
Missing edge text or heavy-looking print, signs of a redrawn dial.
Sources: Seiko7A38 forum. Our own photo comes with our first shoot.
Chronograph Center seconds, 1/20-second and minute counters all run and return to zero.
A counter that won't move (one repair traced a dead minute counter to a loose coil wire) or hands that don't zero. Seiko's guide has a procedure to re-zero the hands, so ask before assuming the worst.
Sources: Seiko 7A28A technical guide; The Watch Bloke. Our own photo comes with our first shoot.
Battery compartment Clean contacts and no corrosion when the case back is off.
Battery leakage, which can damage the circuit board and the dial.
Sources: Seiko7A38 forum. Our own photo comes with our first shoot.
Movement and pushers A 7A28 movement with pushers that line up and spring back.
A 7A38 movement in a 7A28 case, or brittle pushers on the Ripley's side extension.
Sources: Seiko7A38 forum; collector guide. Our own photo comes with our first shoot.
Common faults and service
The movement is tough. What hurts it is a leaking battery left in too long.
Battery leakage inside
A chronograph counter that doesn't move
Brittle pushers on the 7000's side extension
The 7A28 isn't on Seiko USA's list of calibers it won't service, but its price list has no quartz chronograph line. Worn & Wound notes the metal movement can be taken apart, regulated and repaired.
Not on Seiko USA's list of calibers not to send (checked 2026-10-26). Seiko USA notes other old calibers not listed may also be returned unrepaired.
Where to look
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Why collectors like the 7A28
Seiko introduced the 7A28 in 1983 as the world’s first analog quartz chronograph. It times to 1/20 of a second, with a 30-minute counter and a split-time function, according to Seiko. Inside is a 15-jewel movement with metal gears and plates that a watchmaker can take apart, regulate and repair, as Worn & Wound points out. That’s the reason it has a following that most quartz watches don’t.
The 7A28 has no date. If a 7A28 listing shows a date window, check the case back: it may be a 7A38, a related movement with a day and date.
The four best-known references
- 7A28-7000 “Ripley”: Giorgetto Giugiaro’s design, with a round case and a rectangular extension on the right holding the pushers. Sigourney Weaver wore one in Aliens (1986). Some articles, Worn & Wound’s among them, give the Ripley as a 7A28-7001, a sibling in the same case. Fratello gives about 43 mm across. aBlogtoWatch, looking at an original in Seiko’s museum, notes orange hour and minute hands and a case mixing steel and aluminum.
- 7A28-7010: a Japanese-market Speedmaster with a hooded tonneau case. Plus9Time’s scan of a 1984 Seiko sports brochure lists it as SAY010.
- 7A28-7020: a round chronograph with lugs, long linked to the 1985 Bond film A View to a Kill. That link is disputed; Bond Lifestyle noted in 2023 that the film watch might be a 7A38-7060.
- 7A28-7040: a 7A28 with a rotating bezel, sold in Japan and abroad. The Japanese version prints CHRONOGRAPH above QUARTZ; the export version has a script Chronograph and SPORTS 100, according to collectors. Neither is a redial.
The RAF 7A28
The Royal Air Force issued the 7A28-7120 from October 1984 to November 1990, according to Worn & Wound, which puts the total at 11,307. Originals have a bead-blasted case, a fixed bezel without markings, fixed strap bars, a circled P on the dial for promethium lume, and military stock numbers on the case back. If a watch sold as an RAF issue is missing those details, ask why before you pay for the provenance.
What usually goes wrong
- Battery leakage. A battery left in for years can leak and damage the circuit board and the dial. Ask for a photo with the case back off.
- A counter that won’t move. In one repair, The Watch Bloke traced a dead minute counter to a fine wire that had lost contact with its coil terminal; the time still ran.
- Hands that don’t return to zero. Seiko’s technical guide includes a procedure to re-zero the chronograph hands, so this isn’t always a fault.
The 7A28 isn’t on Seiko USA’s list of calibers it won’t service, but its price list has no quartz chronograph line. An independent watchmaker who knows the 7A28 is the safer bet.
Swapped parts
The 7A38 looks similar and some parts will physically fit. One collector put a 7A38 movement in a 7A28-7040 case and found the pushers and the movement levers didn’t line up. Redrawn dials exist too; check that the small text at the edge of the dial is there and that the printing isn’t heavy. Then match the dial and bracelet to the reference and market on the case back.
Sources
- Seiko, Our Heritage and the Cal. 7A28A technical guide.
- Worn & Wound, Seiko 7A28 pt 2: The Quiet Beauty and Time Spec: Seiko 7A28 RAF Gen 1.
- aBlogtoWatch, Seiko Giugiaro ‘Aliens Ripley’; Fratello, The Best Seiko Watches From The 1980s.
- Seiko 7A28 Collector’s Guide and the Seiko7A38 forum: references, dial printing, swaps.
- Bond Lifestyle, Seiko 7A28 7020 Quartz Chronograph; The Watch Bloke, Seiko Gen 1.
FAQ
When did Seiko make the 7A28?
Seiko introduced it in 1983 as the world's first analog quartz chronograph. Collector sources point to production running from late 1982 to around 1991 or 1992; Seiko hasn't published the end date.
Why is the 7A28-7000 called the Ripley?
Sigourney Weaver wore a 7A28 in this Giugiaro case as Ellen Ripley in the 1986 film Aliens. Articles disagree on whether that version is the 7A28-7000 or the 7A28-7001, a sibling in the same case, so the exact reference isn't settled.
Is the 7A28 the James Bond watch?
The 7A28-7020 has long been linked to A View to a Kill (1985), but Bond Lifestyle noted in 2023 that the watch on screen might be a 7A38-7060. The link is disputed.
Can a 7A28 be serviced?
Yes. Worn & Wound notes the 15-jewel metal movement can be taken apart, regulated and repaired.