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Discussion Starter · #1 ·
I have an original Seiko Black Monster (SKX779) with 7s26c movement. I like the watch because of its luminosity and the fact that the crown is at the 4:00 position. (I walk with crutches, and if the crown is at the usual 3:00 position, it digs into my wrist). As my illness has progressed, (I have multiple sclerosis), I am moving less and less. This is causing my watch to run out of power much quicker than it used to.

My question is: "What is the best way to energize the watch? (it can't be hand wound)" The Seiko owner's manual suggested swinging the watch in a big arc for 30 seconds to get it started. I will do this a few times during the day, but it doesn't seem to be all that efficient. Some people have suggested swinging the watch from side-to-side. Does it make any difference if I move the watch in an up-down motion, rather than side-to-side?

The movement is less than 1 year old and its loss of power reserve corresponds directly to when my health took a big turn for the worse. I realize a quartz watch would solve this problem but I've had this watch for many years and would like to keep using it.

Thanks.
 

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Unfortunately, one of the downsides of this movement is its difficulty to keep fully charged. Typically the idea is you need to shake it and then wear it... and move around enough throughout the day to keep the spring wound up. If you don't move around much throughout the day, it's not going to work very well. I've also noticed this movement tends to keep time pretty poorly during the bottom half or so of its power reserve, which doesn't help.

You may want to consider getting a watch winder box and putting it in one of those overnight to keep it fully wound.
 

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Discussion Starter · #3 ·
Thanks for your reply. One of the things I had noticed that whereas the watch used to lose about 5 sec/day, it suddenly started losing 20-30 sec/day. I didn't realize that the watch lost accuracy when it was in the lower part of its power reserve. I am beginning to think that I may have no choice but to buy a winder, as you suggested.
 

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Yeah accuracy tends to degrade as the power runs down on most watch movements. Going from 5spd to 30spd is pretty consistent with what I've seen as well with my SKX when I leave it sitting somewhere for more than a day. It tightens right up once I shake it for a minute and wear it. My NH35 (4R35) powered Invicta behaves similarly.

One of the reasons I love my 6R15 powered SARB033 is that it keeps good time pretty consistently through most of its power arc. It gets loose at the bottom end, too, but not as much and not as soon.

I agree in your situation getting a winder is probably a good idea if you can manage it. It would mean one less thing to worry about.
 

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Unfortunately, one of the downsides of this movement is its difficulty to keep fully charged. Typically the idea is you need to shake it and then wear it... and move around enough throughout the day to keep the spring wound up. If you don't move around much throughout the day, it's not going to work very well. I've also noticed this movement tends to keep time pretty poorly during the bottom half or so of its power reserve, which doesn't help.

You may want to consider getting a watch winder box and putting it in one of those overnight to keep it fully wound.
IME, the watch goes fully wound pretty quickly.

From just a half hour's drive, I'm able to get just under a full day of power reserve. You'd have to be pretty sedentary (as in sit by your desk and never move your hands for hours on end) for this movement to be insufficiently wound. I'm an office worker (most days) and my 7s26-powered watches are fully wound by the end of the day (I judge that by how long it runs after I take it off - generally 40 ish hours).
 

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Discussion Starter · #8 ·
I have been wondering about the poor power reserve. Without a doubt, I don't move as much as I used to, but I didn't think my activity had diminished to such an extent that I would be having power reserve issues. The 7s26c movement is about 8 months old so "old age" can't be a problem. I don't think the movement could suddenly have become defective because it had been very accurate (5 sec/day slow) up until about a month ago. I haven't dropped it or hit it against anything, so I can't come up with any plausible reasons for the sudden change in its performance.
 

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Discussion Starter · #9 ·
i had read that some people had taken a successor movement (I think it was the 4R36 or NH35), and put it into the SKX779 body. I think the only problem with doing that was that the stem needed to be shortened. I don't remember if this is all that needed to be done.
 

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I've found that some of my 7S26's are less sensitive to movement for winding. It may very well be that the rotor doesn't always rotate when the position of the watch shifts unless there is some added force (arm swinging when walking, or deliberate shuffling of the watch in hand). It's no indication of the movements going bad. Tolerances may differ, creating more resistance for the rotor when it must turn to wind the mainspring.

I spend a good amount of time at a desk at work, so for a chunk of the day my watch is rather idle. I favor my modded SKX's with NH36 movements for the sheer fact that I can give them a good hand wind before putting them on in the morning and getting on with my day.

For swapping in the 4R/NH movement, you'll have to replace the stem and crown altogether. The 7S stem does not have the provision for the hand winding mechanism and the SRP779 crown and stem are a single component. The OEM crown for the SRP307/9 should work and has the correct stem.

A movement swap would require the following:
• 4R36 or NH36 movement
• Black date dial for 4R36/NH36 (unless your SRP779 has a 7S26C movement, in which case the date dial should swap to the new movement with the white dial. 7S26A and 7S26B date dials are not compatible)
• SRP307 or SRP309 crown

The following can be swapped over:
• Movement spacer (if an NH36, I believe 4R36's already have the correct spacer)
• Black day dial for 4 o'clock crown position case (with necessary gears and c-clip if the new movement does not include them. New NH36's do, new 4R36's don't)

Hopefully this helps guide your decision making process.
 

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That's what these watch winders are intended for....users who don't move enough to keep the automatic watch running until the next day.

These Seiko movements all have the same mainspring. The only reason one that might have less "reserve" is that the mainspring did not wind fully. If there's a problem, the rotor would be the first thing to check; some might come loose over time. If it needs tightening or re-attaching, the position should be aligned with the "first reduction wheel" per the technical guide so it would work correctly.

This same note also appear in the 7002 and 7009 movement guides; probably some others too (check first before making any adjustments).
 

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