... few more photos 😉

In the meantime I was able to remove the DNA traces with a toothpick. This kind of history removal really doesn't hurt.

Unsigned inner case back with integrated anti-magnetic shielding.

Seiko SKX013, Citizen NY2300-09eb and the 7548-7000

I had to bend the end links a little with the pliers but now it's just about

Dimensions:
Case length: 45.7 mm (lug to lug)
Height: 13.2 mm
Lug width: 22 mm
Diameter (over the crown) 10 o'clock/4 o'clock: 45.5 mm
Diameter 9 o'clock/3 o'clock: 42 mm
Crystaldiameter from top: 31.5 mm

 

I my opinion, the 7548 is the best. Your watchband goes very well with the watch. If you have a reliable watch maker it would be good to give it maintenance. I have not done anything to my 1981 7548 which I bought used. Cheers.

I would like to visit Switzerland someday.

 

I believe the punch mark on the case back indicates when the battery is due for change. Some may argue with me on this subject, but I recently saw a review of a watch by a Seiko restorer from the original owner that was never serviced and the mark was there from day one. Yours dates to 1978 and the punch mark is at 83 or 5 years from the manufacturing date.

 

@Vette Enthusiast
Okay, but if that's the case, then Seiko must have changed something, because I read that the replacement interval is set at three years. Perhaps five years was only recommended for early watches. Later, with a little more experience, Seiko recommended only three years. Is that possible?

 

@Vette Enthusiast
Okay, but if that's the case, then Seiko must have changed something, because I read that the replacement interval is set at three years. Perhaps five years was only recommended for early watches. Later, with a little more experience, Seiko recommended only three years. Is that possible?

Great first posts- keep it up!

Read page two for some more information directly from Seiko on this topic:

https://seikoserviceusa.com/uploads/datasheets/7548A&7549A.pdf

I think the three-year battery life was the spec for the professional version of that caliber family (7548 and 7549) while the standard 7546 is spec’d at 5 years, even though they all take the same battery and all have the same maximum allowable consumption (2.5uA). In my experience all versions can actually achieve 5 years, but it was likely an abundance of caution that made Seiko recommend 3 years for watches that were likely being used by professional divers who depended on their watch as a critical tool. The likelihood of gaskets failing in 3 years vs. 5 is also lower.

You might search around for photos of other 7548s to see the interval between production date and first factory punch mark. According to my personal examples, the three-year span roughly holds, within a few months. Perhaps yours was assembled two years after the case was stamped? I have a 7549 also from ‘78, and the factory battery change punch mark is indeed in ‘81.

 

@Orion1978 - Willkommen und Guten Morgen!

Adding to the excellent comments above, there are two nicknames for the 7548-7000; "Slim Turtle" and "Quartz Turtle." Certain variants have additional nicknames (the 200m 7548-7010 is a "Brian May" for the astrophysicist and member of Queen, and the 7548-700F (and maybe B) is called "Stormin Norman" after Gen Norman Schwarzkopf). I fell hard for 7548s, even after gifting one to my son and another to my son in law, I have more than half dozen including the -700B JDM Pepsi Bezel and the -700C JDM Orange dial.

I'd get it serviced. Unlike most modern throwaway quartz movements, 7548s are made to be serviced and should last for a very long time. 7548s share their mechanical side with the 6306/6309 and parts should be available. The quartz side is interchangeable with 7546s and Pulsar Y513s (also other 7548s and 7549s, but I digress). Any band or bracelet that fits an SKX007 can be used with the 7548s. 7548s be trimmed/adjusted to run within a few fractions of a second a day. These are fantastic watches that are underappreciated. Get it serviced, change gaskets, maybe check waterproof. You might not need to get it serviced again for a couple decades, but for all you know, yours is 45 years old and may never have been touched

I purchased some 7548s that weren't running only to discover they'd never been serviced and the oils had gummed up, stopping it. 7548s are incredibly robust and over-engineered. Adrian at Vintage Time Australia said in a You Tube something along the the lines of "after the Apocalypse, only three things will still be around: Cockroaches, Toyota Camrys and Seiko 7548s"

Your bracelet works very well. Just FYI- the JDM models came on the rubber strap you have, but the US (maybe the rest of the world, not sure) came on Seiko Z199 bracelet (Uncle Seiko sells a wonderful reproduction Z199). IMHO, Uncle Seiko's Razorwire is the most comfortable bracelet I have

Welcome aboard
BarryK

 

Oh..right there in front of me! Looking right at/through it. Well that's pretty clear. ha

 

Different year ranges too! huh

 

Hi everyone,
Thank you for your helpful answers. I'll be happy to study them more closely in daylight.

Here's a better image of my 5-year marker.
So long...

 

Hi everyone,
Thank you for your helpful answers. I'll be happy to study them more closely in daylight.

Here's a better image of my 5-year marker.
So long...

Some food for thought: Nothing is certain with Seiko and anyone (service center or otherwise) with a punch can add one to a case back.

Have a look at the consistency with how close the punches in my photo case backs above are to the hash marks - and they’re all in the first year of the battery change range on the case back.

I won't debate whether your photo's case back has a punch from the factory, you be the judge.

 

@rainier , @Silver_Alert , @barryk , @rileynp , @Vette Enthusiast , @3366carlos

Good morning everyone and thank you all for the helpful, varied and detailed comments!

I'm still new to this field of the "Slim Quartz Turtle" and still learning about it.
However, I've read before that Seiko's documentation is somewhat opaque at times, which only makes things more exciting for us 😆

Thanks for the pictures, the history, the links and the food for thought; that's why I'm here. It's always interesting to learn something new in the discussions, even when it comes to zombie acopolyps. Knowledge can sometimes be compiled from the experiences of different individuals.

One hour ago I have ordered an used Uncle Z199 in nice condition, I don`t like the original Rubberstrap and the actual President bracelet is nice, but I like to have a choice.

The seller told me the watch had been serviced in Tokyo about two years ago, but that could mean only the seal and battery were replaced.

I'll ask my watchmaker if he can perform a service. That would mean disassembling, cleaning, adding new lubricant, and re-sealing it? Or what do you think should be done, when the patient is already on the operating table? I'm not familiar with quartz services.

Have a good start into the new week
Falk

 

@rainier , @Silver_Alert , @barryk , @rileynp , @Vette Enthusiast , @3366carlos

Good morning everyone and thank you all for the helpful, varied and detailed comments!

I'm still new to this field of the "Slim Quartz Turtle" and still learning about it.
However, I've read before that Seiko's documentation is somewhat opaque at times, which only makes things more exciting for us 😆

View attachment 553547

Thanks for the pictures, the history, the links and the food for thought; that's why I'm here. It's always interesting to learn something new in the discussions, even when it comes to zombie acopolyps. Knowledge can sometimes be compiled from the experiences of different individuals.

View attachment 553535

One hour ago I have ordered an used Uncle Z199 in nice condition, I don`t like the original Rubberstrap and the actual President bracelet is nice, but I like to have a choice.

View attachment 553546

The seller told me the watch had been serviced in Tokyo about two years ago, but that could mean only the seal and battery were replaced.

View attachment 553545

I'll ask my watchmaker if he can perform a service. That would mean disassembling, cleaning, adding new lubricant, and re-sealing it? Or what do you think should be done, when the patient is already on the operating table? I'm not familiar with quartz services.

Have a good start into the new week
Falk

The seller allegedly had it serviced 2 years ago, but we don't know what that means. To be honest, you might consider putting off service till the battery goes in 2-3 years. Another great thing is that this watch adopted the Astron's feature of having the second hand jump in 2 second intervals indicating its time to replace the battery). Once you need a new battery, why not have a watchsmith change the battery and poke around to see if it needs more than that. I'd be careful washing your hands till then. Or you could possibly have it pressure tested and if it doesn't pass, get it serviced

 

Welcome to the site Faulk! I bought my 1st 7548 (late to the party) only a few years ago and I had a 44G1ZZ jubilee for an SKX sitting new in it's bag. I installed the bracelet and fell head over heels in love with the watch. So much so that I also bought a beater example and my older Son bought one as well, both SQ versions. I then purchased a set of VTA gaskets for both of mine and installed them, the crown gasket is a pita. My younger Son has a very small wrist and I found a 6458-6000 for him and he loves it, so if you would like a 38mm version, sorta, they are very cool models with over the top details and finishing. Enjoy your new find

 

I then purchased a set of VTA gaskets for both of mine and installed them, the crown gasket is a pita.

Why is the crown gasket troublesome?

 

@vincentg
Thank you, too.
If I were to buy a smaller Seiko diver's watch, the SBCM027 would probably be my favorite, but for now I am happy
Greets, Falk

 

@vincentg
Thank you, too.
If I were to buy a smaller Seiko diver's watch, the SBCM027 would probably be my favorite, but for now I am happy
Greets, Falk

I would love to find an SBCM to gift to my Son

 

... that would definitely be a timeless and very nice gift 🤩

 

Welcome! 7548 is a fine beast. Super comfy and robust. Can't get enough of them.

Rob

 

Welcome! 7548 is a fine beast. Super comfy and robust. Can't get enough of them.

Rob View attachment 553558
View attachment 553557

You can deduce I don't like the original JDM rubber strap and that I haven't worn 3 of them since DST. My wife liked the orange one so much, I got her one (not pictured here). Additionally, I have already given away two (obviously not pictured) to my son and son in law. Maybe I'll declare next week 7548 week and wear a different one each day. @scubarob99, are you up for the challenge?

 

Lovely 7548's posted, They are among my favorites Just serviced one yesterday....

 

 

This photo makes it obvious he is not wearing a Rolex, the "president" style bracelet was never offered as tu-tone, as well as the dial markers are wrong for a Rolex.

 

Hi @3366carlos

That is the "Stromin Norman" and on the other wrist he`s wearing a Rolex.

Here I found another interesting website about different watches from different military groups.

WOE Dispatch

Former CIA Case Officer with a passion for timepieces. A watch community for like-minded people that believe in honoring our history and using our tools. In the world of espionage, time matters.

www.watchesofespionage.com

I really like my "new" watch 🤩

 

Several sources dispute the Rolex theory, stating it's a Seiko dress watch that LOOKS like a Rolex. If memory serves it's reputable sources, like DCVW. Maybe I'll look later

 

I have been going through my 7546/8 parts recently and building a fair few movements. Whilst stripped I tend to jewel the centre wheel and upgrade any metal pivots to jewels in the 7546/8 series. The centre wheel upgrade is not for the faint hearted as the plate is pretty thin in this area, the high torque of the movement can wear the plate hole in this area over time. In affected movements you will see this wear accentuated during time setting.

Here is a 7546-606A I’ve just finished for my daughter, note the extra jewels in the bridge.

 

@Edinburger
I'm (unfortunately) not a watchmaker, so I can only partially comprehend the labor involved. In any case, it sounds like the long durability often attested here; the movement must be truly indestructible with your modifications. Congratulations, and thanks for sharing.

 

I skimmed the text and only saw "Rolex" somewhere...
I'll have to google-translate it after work.

 

Was it a 700B?

 

Was it a 700B?
View attachment 553728

SHORT VERSION: "After further review," I think it could have been either a 7548-700B or a -700F

LONG VERSION: This is complicated. Look at Complete Guide to the Seiko Slim Turtle 7548
Both the 700B and the 700F were Blue dialed Pepsi bezel for the export market (which you would expect him to have, likely buying at a PX). Now scroll to the top of the same link and you will see that the -700B is listed as JDM. So -700B was both JDM and ROW (rest of world) while -700F was only ROW. Either way, yours could be it (but technically mine isnt because I have a JDM -700B)

Anyone else have anything to add?

 

While there is some solid information in the Seiko Guy's link you shared above - that which I have a ton of respect towards his documentation, his production dates are not accurate for the 7548 references. I've documented actual case backs in my 7548-production thread I posted earlier, that go a bit beyond what he's listed.

This is not new information, but relevant and the latest version (I believe) from Tiger John and others here at SCWF. This table is a great resource for references (but does not include production dates). Someday I'll have to carry on and update this with some more details/production info:

 

Great watch. Back in ‘78 the 600m quartz would have been like 120,000 yen, the automatic 600m 89,000 yen, a 6138 and a 6309 around 20-25,000 yen. The 300m quartz around 60,000, and 35,000 for the 150m 7548.

my recollection from the era where the PX/BX watch cases in mid to late 80s the Seiko shelf had the 6309s for about 130 to 150, the 7548s for over a hundred more, and the Aqualand 200s in the little scuba display and H558s were over 300 bucks.

 

I think I may like the 7548…..there are more kicking around my collection but here is a sample. Recently was bidding on the rare 200m 7548 orange (701A) but dropped out the as ithe price went too rich for me.

 

For the love of god, let's not let the nick name be associated with "turtle." 🤮🤮🤮 =)

<* shark >>><

 

@Thesharkman , it doesn't look like a turtle, but then again it doesn't look like a cushion either. I almost always call this a 7548. IF I call it a slim turtle or a quartz turtle, most here understand. If you say "Seiko cushion case," I immediately think of 7005s and the like. If you say "Seiko cushion case diver," I think of 6306/9 700x and 704x, not this. Besides, my experience when I wear my 7548s in public, the vast majority of people who think they have a clue what it is, think its a SKX. We can all call it whatever we want (I mainly call it a 7548) but I love 'em

 

Hey, Mr. Sharkman, you don't have to eat them, I mean the turtles, or where does your objection come from?
OK, I understand, your username... but the idea for the "Turtle" comes from somewhere? I think it's because of the typical case shape of the 6309-7040, and its smaller sister watch, the 7548-7000, is the "Slim Turtle," which makes sense for me. The turtle, after all, is also, in a figurative sense, an "underwater creature" that has to hold its breath to avoid drowning. I think that's a good fit for a diver's watch.

 

Hey, Mr. Sharkman, you don't have to eat them, I mean the turtles, or where does your objection come from?
OK, I understand, your username... but the idea for the "Turtle" comes from somewhere? I think it's because of the typical case shape of the 6309-7040, and its smaller sister watch, the 7548-7000, is the "Slim Turtle," which makes sense for me. The turtle, after all, is also, in a figurative sense, an "underwater creature" that has to hold its breath to avoid drowning. I think that's a good fit for a diver's watch.

The 6309s were originally referred to as "cushion cases." Not sure where turtle came from....but it's a term that I will never use. =)

<* shark >>><

 

OK, I see. In German-speaking countries, we often use anglicisms; it seems more memorable, especially for nicknames.
But sometimes the names are really stupid, though. Oh well, as long as the other person understands what it's about, it's fine.
Have a nice afternoon, @Thesharkman.
Greetings, Orion