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Silver Hawk

More On Elgin 725...

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Then the question I'm sure everyone's been asking or should have been why is there only one half of a watch. It should be plainly obvious what filled the other part of the case in a rather nice green color.

I think no-one was asking because in every reference to 725s, the assumption was that they took standard button cells -- either one or two. So borrowing Larry's photo below, the clip is to hold two button cells. I just assumed your clip was missing from the movement.

dscf0165t.jpg

So what are you saying? That early 725s took this bespoke battery? :huh:

Great to see this green thing BTW.

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The references for the destruction are very reliable but it still leaves us with unanswered questions. The service manual was printed in two versions one for one battery and one for two batteries printed in 1961.

Then I'm attaching a few more photographs that will partially answer one of Larry's questions and probably generate new questions. One of photographs shows a 722 square diode on the bottom of a 725 coil. It probably explains why there's a convenient hole in the main plate. When I was looking for a movement to get a picture of the invisible diode I noticed this one.

Then the question I'm sure everyone's been asking or should have been why is there only one half of a watch. It should be plainly obvious what filled the other part of the case in a rather nice green color. Then for a Larry's question a group photo showing just how small is 722 is.

John

Img_5494s.jpg

John,

These pictures are great!

In your comments above, you mention that there were two versions of the service manual printed for the 725. Other than the obvious difference (one battery versus two batteries) why would there be a need for two manuals? I'm assuming that there were there other changes made with release of the single battery version?

I've noticed that there are a variety of different battery clips shown in the pictures of the 725 movements posted. Looks like the designers were constantly looking for different improvements to try.

That green battery pack is very interesting! Given that it would have been designed in a period when the button cell probably didn't exist and that it was built with what appears to be a plastic housing. There were a lot of engineering principles applied in it's design, both from a materials and intended application point of view. It is an elegant solution to what must have been a very difficult problem.

Of course that begs another question which you may or may not be able to answer, what battery was used with the 722 movement? When I saw your photo, I did wonder what battery would have been used and just assumed it was a single button cell.

You are correct, your photo's are raising a lot more questions.

Larry

Edited by Larry from Calgary

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I seem to been the cause of a revival of interest in the finer points of these esoteric watches. They are better with Paul than with me! On the point of the diodes I can perhaps add a little. Remember these watches were designed by watchmakers who perhaps had little knowledge of the elementary principles of simple electric circuits. A description in words may help. There is a series circuit of the battery, the coil and the contact set. When the contacts are closed, current rises in the inductance of the coil, the rising magnetic field accelerates the balance and the contacts break. Now, the current wishes to continue to flow in the inductance, so, the voltage rises across the contact gap and the stored energy in the inductance is dissipated very quickly in the resulting spark across the contact gap. This spark of course erodes the contact material. Think of the Hamilton. It was common practice at the time to use a diode across the coils of magnetic relays which were in commom use at the time. So, enter the diode in the Lip and the Elgin. However, the diode supresses the spark by providing an alternate path for the current which continues to flow for a longer time, the decaying magnetic field taking energy from the balance the force being in the opposite direction to that which accelerated the balance. If anyone has the time try disconnecting the diode and you should observe an increase in balance amplitude. So, contact erosion or a low Q oscillatory system.

The Hamilton was quite a good watch until the contacts gave out. I suspect the Elgin/Lip were not quite as good.

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:rltrlt:

Thanks again John for posting the picture of the green Elgin designed and manufactured power cell. It's hard to comprehend the level of design skills and the leading edge efforts required when this battery was first engineered, in say 1952 or shortly after. It's amazing to see just how much of an effort Elgin chose to undertake to design and manufacture "the watch of tomorrow".

I've always wondered why the battery clips appeared to be an afterthought. Now I know.

dscf0165t.jpg

Not much there to hold the batteries in a correct position which probably lead to a lot of intermittent failures.

:cheers:

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My apologies for not getting back to you sooner as one of Paul's questions has been bothering me. I think I may know the answer but I wanted to do more research before I let you know the answer.

Larry I'm going to give you some partial answers and a picture you requested. The reason why there are two manuals is I don't think they knew which one they were going to sell at the time they printed the manual.

The picture shows one of the few 722’s in a case. Unfortunately I'm missing the photo of the back but it gives you an idea of how the 722 fit in the case. You'll notice there is no screws on the movement for attaching the battery. When I have a chance I will take some photographs of the side of the movement so you can see how the battery would've made contact.

John

722.jpg

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My apologies for not getting back to you sooner as one of Paul's questions has been bothering me. I think I may know the answer but I wanted to do more research before I let you know the answer.

Larry I'm going to give you some partial answers and a picture you requested. The reason why there are two manuals is I don't think they knew which one they were going to sell at the time they printed the manual.

The picture shows one of the few 722’s in a case. Unfortunately I'm missing the photo of the back but it gives you an idea of how the 722 fit in the case. You'll notice there is no screws on the movement for attaching the battery. When I have a chance I will take some photographs of the side of the movement so you can see how the battery would've made contact.

John

722.jpg

John,

"I don't think they knew which one they were going to sell at the time they printed the manual" sums it up quite nicely.

I did notice that there were no battery screws on the 722 and realized that the 725 battery would've been too big. I'll make a guess that there was a slot in the movement base for the battery tabs to slide into. It was likely this battery that caused most or a lot of the design problems for the Elgin designers.

The 722 dial design is very similar to Wittnauer electric that Paul has. I noticed that it says "Lord Elgin" but wasn't the 722 supposed to be a ladies watch (Lady Elgin)?

Larry

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I found my information regarding the 910. I also have a considerably longer story which would take several paragraphs. So I'm going to give the extreme short version unless someone shows interest in the longer version. The photograph is of a patent filed October 14, 1963. It is not exactly the same as the 910 but extremely close. Besides the US patent there was also a Swiss and French version of this patent.

John

910.jpg

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I found my information regarding the 910. I also have a considerably longer story which would take several paragraphs. So I'm going to give the extreme short version unless someone shows interest in the longer version. The photograph is of a patent filed October 14, 1963. It is not exactly the same as the 910 but extremely close. Besides the US patent there was also a Swiss and French version of this patent.

John

John,

The patent below then is not the 910 but another planned release? I for one would like to read your longer story. :notworthy:

Regards,

Larry

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I found my information regarding the 910. I also have a considerably longer story which would take several paragraphs. So I'm going to give the extreme short version unless someone shows interest in the longer version. The photograph is of a patent filed October 14, 1963. It is not exactly the same as the 910 but extremely close. Besides the US patent there was also a Swiss and French version of this patent.

John

John,

The patent below then is not the 910 but another planned release? I for one would like to read your longer story. :notworthy:

Regards,

Larry

I think I can see the difference! They went back to the shorter coil styled after the one used with the 722, mounted it at one end (opposite the balance wheel) like the 725, with an external diode like they used in the 910.

Am I correct?

Larry

Edited by Larry from Calgary

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I think the 910 is a slight evolution beyond the one in the patent. The coil is slightly shorter and the arrangement of the screws are different. You'll notice the holes for the screws are really slots as opposed to 725 holes. To understand this I have a picture with three of the coils. You'll notice the 722 coil is considerably shorter than the others. The middle one very likely is the one from the patent and for comparison there's a 725 coil.

Then the side photo of the 722 showing the contact for the battery. Then two pictures of a 722 next to one of the prototypes from 1952.

The reason for the small size of the prototype this was a project that began in the 30s and the watch was supposed to be sized the same as the watches at that time.. It's a shame they didn't start with a pocket watch and go the other direction.

John

Img_5523s.jpg

Img_4639s.jpg

Img_5515s.jpg

Img_5517s.jpg

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So who picked this up then?, I think the seller thought it was going to make a lot more than this. Item No 390175246429

No idea. :whistle:

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I think the 910 is a slight evolution beyond the one in the patent. The coil is slightly shorter and the arrangement of the screws are different. You'll notice the holes for the screws are really slots as opposed to 725 holes. To understand this I have a picture with three of the coils. You'll notice the 722 coil is considerably shorter than the others. The middle one very likely is the one from the patent and for comparison there's a 725 coil.

Then the side photo of the 722 showing the contact for the battery. Then two pictures of a 722 next to one of the prototypes from 1952.

The reason for the small size of the prototype this was a project that began in the 30s and the watch was supposed to be sized the same as the watches at that time.. It's a shame they didn't start with a pocket watch and go the other direction.

John

Img_5523s.jpg

Img_4639s.jpg

Img_5515s.jpg

Img_5517s.jpg

John,

You're leaving me with more questions with each post you add. You mentioned that this project was started in the 30's? I am amazed at the technology they were trying to develop. If one were trying to design a miniature battery without seeing one they'd probably come up with something that looked just like the one they did. Do you know what kind of electrolytes they used in its construction?

Were there any watches released for sale with the Elgin designed battery or did Elgin drop this R&D exercise in its entirety?

I am enjoying your stories and pictures.

Larry :notworthy:

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One of the things you want to remember when Elgin was trying to make an electronic watch that it was an incredibly diverse company making things way beyond watches. They had an electronic division producing very small relays, microphones and they were researching transistors.. They were producing a lot of things for the military that was using electrical components.

The battery uses indium and some of the specifications of interest it's not supposed to leak and can be manufactured in almost any desired shape. From the literature I have their actively promoting their battery in 1955 and after that I don't see any mention of it. They did file several patents for their battery. It looks like the last one was filed in November 1956.

The only real clue we have as to when they dropped their battery was they had both 722 and 725 movements in 1956. The 722 was obviously designed solely to use their battery. The 725 had options with the screw terminals.

As you like pictures I have a copy of the warranty card. From the very tiny number printed on the card they printed it July 1962. Then because it was an odd size to scan I overlapped the middle as it unfolds in three separate pages. Then pictures of the replacement Mallory W-1battery that has the same date as the warranty card. Unfortunately it's hard to see the battery as it didn't last forever and has leaked.

John

Elgin_w1.jpg

Elgin_w2.jpg

Elgin_w3.jpg

Elgin_w4.jpg

Elgin_b1.jpg

Elgin_b2.jpg

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One of the things you want to remember when Elgin was trying to make an electronic watch that it was an incredibly diverse company making things way beyond watches. They had an electronic division producing very small relays, microphones and they were researching transistors.. They were producing a lot of things for the military that was using electrical components.

The battery uses indium and some of the specifications of interest it's not supposed to leak and can be manufactured in almost any desired shape. From the literature I have their actively promoting their battery in 1955 and after that I don't see any mention of it. They did file several patents for their battery. It looks like the last one was filed in November 1956.

The only real clue we have as to when they dropped their battery was they had both 722 and 725 movements in 1956. The 722 was obviously designed solely to use their battery. The 725 had options with the screw terminals.

As you like pictures I have a copy of the warranty card. From the very tiny number printed on the card they printed it July 1962. Then because it was an odd size to scan I overlapped the middle as it unfolds in three separate pages. Then pictures of the replacement Mallory W-1battery that has the same date as the warranty card. Unfortunately it's hard to see the battery as it didn't last forever and has leaked.

John,

On the warranty card for watch model it says "See number stamped on back of watch". Do you have an example of the number sequence breakdown? Does it list model number and movement type?

Larry

Elgin_w3.jpg

:dontgetit:

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Wow! Thanks so much for those scans of the warranty card and battery. I love this early literature. :thumbsup:

John, would you mind emailing me please at paul@electric-watches.co.uk ?

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Larry

To answer your question we're going to have to assume something that the case in question is the model 2051. This is the most common one people have, the 10k gold filled one either with the battery hatch or without. Then the reason to assume it's this case is it's the only one with the serial number on the back of the watch and it's the most common case found.

Officially there's nothing left to explain what the serial numbers mean. But I have a database of all the cases I've been exposed to. There's several things you learn by looking at this case despite having one model number it comes in two variations. On casual looking some of them did not have battery hatches. But casual looking does not reveal some of the confusing things. For this model number none of them originally had an opening for the battery. If you look at the information stamped inside the case it's in the center. When they put the opening in the stamping has been somewhat removed. If you look at the stainless steel case where obviously the battery was definitely not an afterthought. The maker's name, model number and serial number are very readable to the side of the opening. On some cases you have not seen when they put the battery opening in you can not even read the model number or the serial number. Then there is the other minor problem the cases without openings for batteries are designed slightly differently. The engraving on the back and the serial number are in a different location. Then the Crystal fits differently rather than a groove inside the case there is one on the outside. Almost like a different model number but they do have the same model number inside if they left enough of it to be read.

So if we look at the lowest serial number I have and the highest serial number and a little math we come up with about 12,000 serial numbers. The problem with the database they are is only 55 cases in it. But the spread of numbers I have looks very good. The meaning of this is the lowest serial number is 56xxx and the highest 68xxx. So numerically we have a 56 and 57 that it jumps to 60 where the numbers are consistently spread out to the end. So worst case we are missing a couple of thousand in the middle possibly.

Other little confusing things the first seven serial numbers are missing openings for the battery. Then they are scattered randomly to the very last serial number which does not have an opening. Then for those of you keeping score 19 of those are missing the openings. Then those 18 have plastic glued inside the case because it was necessary if you are using the cell strap for two batteries. Then the only watch ever found in this case has been the 725.

In case you're still not confuse I have attach some photographs one of them is a case you haven't seen it is 14k gold filled and you'll notice that we can't read the model number or the serial number. Then two pictures of the different styles of 2051 case. This particular case without the opening for the battery also has additional milling inside.

John

Img_5526s.jpg

Img_5527s.jpg

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Larry

To answer your question we're going to have to assume something that the case in question is the model 2051. This is the most common one people have, the 10k gold filled one either with the battery hatch or without. Then the reason to assume it's this case is it's the only one with the serial number on the back of the watch and it's the most common case found.

John

Thanks John,

It's quite easy to see the model number in this shot

dscf0167.jpg

Thanks,

Larry

I have another question. In your photograph there is a plastic piece fixed to the bottom of the case. Was this to isolate the battery(s) from the case or to isolate the movement from the case? The reason I ask is because in the next picture you can clearly make out two dark circular shadows which I believe to be caused from the batteries. Therefore the plastic strip must have been to isolate the movement? Why? You may not be able to answer this, but I suspect it was to try and isolate a phenomena that I haven't come across in a long time, relay "Drop-out".

dscf0123a.jpg

John, do you know what the following part (read plastic piece) is used for?

7a4f1sv6.jpg

Here is the rest of the watch shown in the pictures above. The red thunder bolt second hand seems rare.

54179333ot0.jpg

Larry

Edited by Larry from Calgary

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Larry

Attached are photographs showing the different arrangements for batteries. Whether you have one or two batteries someplace they have insulation. For the two batteries the installation pieces is found in the case. Then for one battery is on the dial. If you look carefully at the case you have you can see where the insulation was once was as a slight yellow discoloration. The dark circles on the dial were probably caused by the leaking battery and the reaction with silver plating of the dial.

The red plastic thingy is the movement holder for servicing the watch. They seem to be more scarce than the watches. Combined with the metal battery clip you could run the watch outside of the case.

As you've noticed with the lightning bolt red hand Elgin was trying lots of different design ideas.

John

Elgin_Battery1.jpg

Elgin_Battery2.jpg

Elgin_Battery3.jpg

Elgin_Battery4.jpg

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For the two batteries the installation pieces is found in the case. Then for one battery is on the dial. If you look carefully at the case you have you can see where the insulation was once was as a slight yellow discoloration. The dark circles on the dial were probably caused by the leaking battery and the reaction with silver plating of the dial.

Elgin_Battery3.jpg

John,

In the two battery watch, the insulation would be placed under the movement. Was the intent to completely isolate the movement from the case [battery (+) POSITIVE]?

Larry

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John,

Of course I have one last question regarding the Elgin Electronic.

Shortly after WWII, there was a technology exchange between Elgin and LIP regarding their research and development of the electronic watch. So the big question is......who gained the most?

Is the LIP R27 the result of USA based research at Elgin, or is the Elgin 722/725 a result of France based research at LIP? In other words who benefited more from the electric watch research and technology exchange?

Larry

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For the two batteries the installation pieces is found in the case. Then for one battery is on the dial. If you look carefully at the case you have you can see where the insulation was once was as a slight yellow discoloration. The dark circles on the dial were probably caused by the leaking battery and the reaction with silver plating of the dial.

Elgin_Battery3.jpg

John,

In the two battery watch, the insulation would be placed under the movement. Was the intent to completely isolate the movement from the case [battery (+) POSITIVE]?

Larry

Larry

The reason why the insulator is in the case is to keep the negative terminal of the battery shorting to the case. It would be much better if I had a picture of the side view but I couldn't find a suitable battery. If you did have a side view we see that the negative terminal of the battery and the battery connector are even with the movement. Then as the movement is only held in with the movement ring it's somewhat free to move around so I think the fear is it's going to touch the back of the case.

John

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John,

Of course I have one last question regarding the Elgin Electronic.

Shortly after WWII, there was a technology exchange between Elgin and LIP regarding their research and development of the electronic watch. So the big question is......who gained the most?

Is the LIP R27 the result of USA based research at Elgin, or is the Elgin 722/725 a result of France based research at LIP? In other words who benefited more from the electric watch research and technology exchange?

Larry

Larry

For the question of who gained the most that's a very good question that I don't have an answer for.

From the material I have lip did have their own electric watch when they approached Elgin. You do have to wonder why a company that has a successful product would approach another company unless they were having a problem. If you look at the various generation of Elgin watches you'll see they follow a common theme and they look more or less the same being improved with each generation. Then as you've now seen the 910 what would the next watch look like after that? I've attached a copy of a letter from Dr. Challacombe the second paragraph is the one that you should find interesting.

John

Elgin_Feb_7-1963.jpg

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John,

Of course I have one last question regarding the Elgin Electronic.

Shortly after WWII, there was a technology exchange between Elgin and LIP regarding their research and development of the electronic watch. So the big question is......who gained the most?

Is the LIP R27 the result of USA based research at Elgin, or is the Elgin 722/725 a result of France based research at LIP? In other words who benefited more from the electric watch research and technology exchange?

Larry

Larry

For the question of who gained the most that's a very good question that I don't have an answer for.

From the material I have lip did have their own electric watch when they approached Elgin. You do have to wonder why a company that has a successful product would approach another company unless they were having a problem. If you look at the various generation of Elgin watches you'll see they follow a common theme and they look more or less the same being improved with each generation. Then as you've now seen the 910 what would the next watch look like after that? I've attached a copy of a letter from Dr. Challacombe the second paragraph is the one that you should find interesting.

John

John,

That is a very interesting document indeed. It is easy to see the similarities between the LIP and Elgin designs. There have been comments in our posts relating to the similarities. It's my understanding that the LIP R-148 was one of their more successful movements in the number of sales. The R-148 also has a reputation of being a very robust design.

One can only wonder what Elgin might have been able to do with their electronic watch designs had things turned out differently, or if fate had been a little kinder.

Do you have any projections of what the next watch might have looked like?

Larry

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The R-148 also has a reputation of being a very robust design.

The R-148 / 184 is a great movement in my experience. The only time it doesn't run is when its been damaged by a careless watchmaker; they either wreck the two contact wires or damage the coils. But the movement never seems to fail on its own accord and doesn't "wear out" like the Hamilton 500 and 505.

It must have been a good seller for LIP as well; it turns up in many different brands of watch.

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