Mystery of P1 serial numbers solved...partially, at least

[bruce wegmann]

I was going through some of my spare parts last night and came across a caseback with the serial number P970145. And that looked terribly familiar... Until now, no one has had a suggestion why the P1s had such an odd serial number block. Why the "P" prefix [again, the only Pulsar numbers with a prefix of any kind], and why such an early watch would have such high numbers. I think I have the missing part of the puzzle. This is a stainless back to a Hamilton one-button model. So the answer would seem to be...the P1s have this serial designation because...it's NOT a Time Computer serial number...it's a Hamilton serial number! Probably put there, at the Hamilton facility, at the same time the HAMILTON name was stamped onto the P1 casebacks. I consider the chance of this being just a coincidence, and having the same letter prefix, to be as near zero as it gets in this universe [although why this particular block was chosen is still anybody's guess...it could have been completely arbitrary]. Check out all your early Hamiltons, gentlemen; I'm willing to bet there is one even closer to the magic 754xxx block than mine. And if somebody has a better explanation...please, let's hear it!
Now, why the known numbers span more than the number of watches actually made...that's another question entirely, and I think I
may have a guess to make about that, too, but one thing at a time.
Oh, and I'm still looking for more Hamilton-marked P2s...especially in stainless...where are those???

[bucko170]

I've never seen a P1 case back, could you post a photograph for those of us not lucky enough to own a Pulsar P1 to see.

Now, why the known numbers span more than the number of watches actually made...that's another question entirely, and I think I may have a guess to make about that, too, but one thing at a time.

Could it be possible the P1's where just added to the existing Hamilton production line - if you could find corresponding Hamilton serial numbers to fill the gaps between the P1 serial numbers it could help support this theory.

[bruce wegmann]

I think the P1s are a good example of a 'serial number block"...a continuous run of numbers within fixed upper and lower limits...like the 14K Pulse/Time. They start at 501, go to 600, and that's it. But I don't imagine we'll fnd a stainless caseback within the P1 block; as far as I can see, they never mixed types inside a block. So, let's get out those Hamiltons, and see how close we can get; I have found another in the P976 range, so there are others out there, for certain.
P.S. Bucko, back in March you posted that you had a chance to WEAR a P1...and you never looked at the back...?

[bucko170]

P.S. Bucko, back in March you posted that you had a chance to WEAR a P1...and you never looked at the back...?

I was to busy admiring the front to notice the back

[bruce wegmann]

Well, I guess you can be forgiven for that... I'm still thinking there must be a fair number of those Hamiltons around; time to dig through those boxes and see how close we can get to that all-important 754 block.

[rklumpp]

Hi, I have found a stainless steel case back which says on one side
"Hamilton Watch Co. 999573" and on the other side is the number
P969594.

Does this help?

[bruce wegmann]

Of course it does; every new piece of the puzzle fitted into place gives us a slightly better view of the overall picture. BTW, I understand the other set of digits...999573...gives the model/style number...999...and the last three are a date code, 5/73, so your Hamilton dates from May of 1973. It is probably not a coincidence that your watch was made after the P1s and has a higher serial number.

[bucko170]

and the last three are a date code

Works for mine 906575 - May 1975, it's a dot display so I expected it to be earlier, maybe it has had a replacement module?

[azimuth_pl]

serial number blocks are used in many areas of the economy.
the planning department plans demand and production and gives you a set of numbers for each particular product or service.
if sales exceed the block you are then given a new set of numbers.

this allows to plan production/sales/services in advance for each particular type, however the drawback is that the production might not reach the limit of the block. so there might (will be) some empty gaps in between for the numbers that were never used.

[clockace]

this is not a p1 obviously, but i just acquired a very beatup hamilton led that has a 10k gf case and bracelet. it has a hamilton 834 module, hr, min, sec, date, mo, and day of wk. the s/s caseback has the #9065376. by cleaning up the contacts and 2 new renata 357's it lit right up. while the bracelet is very poor cond, the case and almost flawless red glass are good. the hamilton logo and name on the lower edge of the glass are near mint. now the search for a better bracelet. peter

[azimuth_pl]

that must be a late Hammy with alphanumeric Frontier module (most likely Fr2003) used also in the Omega Constellation 1603.

These are my Hamilton product and serial numbers:
Frontier modules - 9028376, 906675, 906675
Pulsar modules (P2&P3):
all steel:
998974 / 101914,
998974 / 104435
goldfill, steel back:
999573 / P976011,
999573 / 43727,
998874 / 066530,

[clockace]

how late would you say. i noticed 1 of the frontier versions you listed has a 7 digit ser # also. from the condition of the bracelet on mine i would say it was worn daily for many years possibly by an older person as there is much dead skin and grime inside the links. the link system on this version appears to be a poor design also. the backside has a single springbar in the middle of the link allowing it to tip like a teeter-totter. this allowed the steel crossbar in the top links to wear away on the semicircle that is in the top links. after the corners wore away this would allow the top links to drag out to the edge of the link creating huge gaps in the bracelet. not sure if this makes much sense w/o a photo. peter

[azimuth_pl]

these Frontier modules were the last LEDs by Hamilton and Omega.
(the next watches contained LCD modules by ESA/ETA).

Fr2002=1602 with dot-matrix Pulsar display by Litronix and then the very last Fr2003=1603 with day of week display also by Litronix *

post a picture of your model from the gallery of ledwatches.net

*well, all Pulsar displays were made by Litronix - a P4 below - it's rear to see a Pulsar signed by a subcontractor.

[bruce wegmann]

Beautiful shot of signed LED die. I have a P3 with similarly signed LED chip in the display. The ones with the more circular light-emittiing area with the six short "fingers" pointing inward were made by Monsanto [so it is not correct to say that all came from Litronix]. Time Computer had many subcontractors, and most of the parts they made were signed; every case made by Star Watch Case Co. has their distinctive "star" logo right next to the Time Computer signature, and all the different bracelet manufacturers signed their parts, as well. Even the clock chips were signed by RCA [the primary supplier] and Hughes. And, BTW, no production Pulsar ever had a "dot matrix" display; that should properly refer to a display format where the characters are formed by selectively illuminating elements of an array of individual LEDs, usually arranged in 5 columns and 7 rows [this arrangement permits full alphanumeric display capability]. How this term got connected to the Pulsar displays [which are dot-segment type], is beyond me, but it is neither accurate or correct [actually a better topic for a separate thread]. Finally, these bonds have been done with a ball-bonder, where a low-voltage spark is used to melt the tip of the wire, and it is pressed into position while the gold ball is still molten. Tends to produce better bond strength between dissimilar metals [here, gold and aluminun], and requires little or no pressureapplied to the substrate [the LED chip]. This technique has undergone essentially no change in 35 years. I have one or two displays that have a short length of gold wire attached to the second bonding pad; evidently the wire broke on the first try, and the technician made a second [successful] attempt.

[azimuth_pl]

dot-matrix :) ....I know, I just try to use the old same wording so everybody will understand.
I know that the cases and bracelets were made a dozen or more subcontractors. I meant that Pulsar modules are unlikely to have a visible signature from a subcontractor. The RCA chip was painted black so the signature was unclear or invisible at all.
Can you post a picture of the Monsanto type as I can't figure it out from your clear description.