¿ªÔÆÌåÓý

Date

Re: How do you decipher HP serial numbers for date.

 

On Thu, Sep 1, 2022 at 10:45 PM, <n8zmTWH@...> wrote:
Never heard that part of it before. So who bought the first A models?
It's still possible that Disney bought his "special" B models before any A models had been sold.


Re: How do you decipher HP serial numbers for date.

 

On Thu, Sep 1, 2022 at 10:07 PM, Jeremy Nichols wrote:
my HP-412A carries serial number 0978A19963. 78th week of 1969? A third example: the 3444A DC Multi-function plug-in for my 3440A DVM ?carries serial number 0973A07281. There must be some additional information we¡¯re missing. ?
Others have mentioned similar examples, and I have to admit that I don't know, but I can suggest two possibilities:

Possibility One: Some projects that HP started in a given year but ran into the next year, might have been given a year code in the year the project was started, or mostly associated with, in order to keep clear what year the project "belonged to." So the week designation would have been 52 + the following year's week. I would expect this to be a rather rare exception to the rule.

Possibility Two: HP wasn't really counting weeks, they were counting something smaller. Suppose you thought one day was too small an increment, plus it requires 3 digits to count up to 365. Dividing the year into weeks gives 52, which only takes 2 digits, but doesn't make good use of those 2 digits. Dividing the year into 5 day increments gets us up to 73 divisions per year, which makes good use of 2 digits but still leaves out both of your examples above. Dividing the year into 4 day increments gets us 91 divisions per day, which makes VERY good use of 2 digits. Since calendars that show the number of days from the start of the year were common back then, this might have seemed awkward, but it would have been easy to figure.

Personally, I lean toward Possibility One. Does anyone have examples of week codes above 78 or above 91? The week code on each of my HP instruments is less than 52.?


Re: How do you decipher HP serial numbers for date.

 

> There's one (maybe more) exception to this: On HP pocket calculators, the date code?IS?the year and week of manufacture.

I don't think that's true, at least not universally.
I have several HP35s with the date code 1143 and it appears many were made with this number - too many for a week's batch, I think.

ref : http://www.vintagecalculators.com/html/the_hp-35_calculator.html


Re: Hp 8590a spectrum analyzer

Richard Cook
 

Yes it's a 50 ohm terminator, not sure if it matters but I bought a 4 pack of NOS HP 50 ohm . I used panasonic? caps. If you need a terminator I'll send you one .
Thanks


Re: Hp 8590a spectrum analyzer

 

Interesting! Is there a terminator on the 1st lo output? I do not have one on mine.


Re: How do you decipher HP serial numbers for date.

 

¿ªÔÆÌåÓý

Thanks, Jeff -- I'd forgotten about the pricing bit. Time to re-read the book.

Someone bought the A models, but I've always wondered who that might have been. Over the years, I've been given two of them, but I have no 200Bs in my collection. Go figure!

-- Cheers,
Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 9/1/2022 21:48, Jeff Kruth via groups.io wrote:

IIRC, the story is in "Bill and Dave" a great book about HP. The A was a mistake in pricing, Bill & Dave guessed at the price (like $67 or so) and found they couldnt make any money at that price. Disney came along and because they wanted "changes" it became a "special", the B model, and H&P upped the price to cover their collective butt (like $78.00)....There may not have been many A models sold.....
Really god book, if you dont have it in your library, pick up a copy. You will like it!
73
Jeff Kruth
?

In a message dated 9/1/2022 11:45:26 PM Eastern Standard Time, n8zmTWH@... writes:
?

Hi Tom¡­Never heard that part of it before. So who bought the first A models?

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: Thursday, September 01, 2022 11:41 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

And that was in addition to calling it the model 200, with an "A" suffix to boot. Dave Packard was very, very smart.

The model that Disney ended up buying was the 200B, by the way. The 200A was a 35Hz-35kHz unit. Disney wanted that shifted downward, to 20Hz-20kHz. Bill Hewlett made some fast tweaks, and the 200B was shipped off to a happy Disney.

--Cheers,
Tom

-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

                

On 9/1/2022 20:35, n8zmTWH@... wrote:

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.

?

?



Re: How do you decipher HP serial numbers for date.

 

IIRC, the story is in "Bill and Dave" a great book about HP. The A was a mistake in pricing, Bill & Dave guessed at the price (like $67 or so) and found they couldnt make any money at that price. Disney came along and because they wanted "changes" it became a "special", the B model, and H&P upped the price to cover their collective butt (like $78.00)....There may not have been many A models sold.....
Really god book, if you dont have it in your library, pick up a copy. You will like it!
73
Jeff Kruth
?

In a message dated 9/1/2022 11:45:26 PM Eastern Standard Time, n8zmTWH@... writes:
?

Hi Tom¡­Never heard that part of it before. So who bought the first A models?

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: Thursday, September 01, 2022 11:41 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

And that was in addition to calling it the model 200, with an "A" suffix to boot. Dave Packard was very, very smart.

The model that Disney ended up buying was the 200B, by the way. The 200A was a 35Hz-35kHz unit. Disney wanted that shifted downward, to 20Hz-20kHz. Bill Hewlett made some fast tweaks, and the 200B was shipped off to a happy Disney.

--Cheers,
Tom

-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 9/1/2022 20:35, n8zmTWH@... wrote:

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.

?

?


Seeking a HP 70000 module retainer screw casting

 

I just received a HP 70001A Mainframe containing 70841B Pattern Generator and 70311A 3.3GHz Clock Source modules.
On the USA leg of its journey to Australia it was poorly packed and the box dropped heavily enough
to shatter one of the diecast metal module retaining screw-nuts. The 8mm hex socket things.

See pic.
Does anyone have one of these screw things to spare? For how much?

Guy


Re: How do you decipher HP serial numbers for date.

 

¿ªÔÆÌåÓý

I've always wondered that very same thing...

-- Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 9/1/2022 20:45, n8zmTWH@... wrote:

Hi Tom¡­Never heard that part of it before. So who bought the first A models?

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: Thursday, September 01, 2022 11:41 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

And that was in addition to calling it the model 200, with an "A" suffix to boot. Dave Packard was very, very smart.

The model that Disney ended up buying was the 200B, by the way. The 200A was a 35Hz-35kHz unit. Disney wanted that shifted downward, to 20Hz-20kHz. Bill Hewlett made some fast tweaks, and the 200B was shipped off to a happy Disney.

--Cheers,
Tom

-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 9/1/2022 20:35, n8zmTWH@... wrote:

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.

?



Power meter advice

 

I currently use HP 438 power meters and am considering upgrading.? Main driver fo upgrade is I'm getting sick of having to enter the cal factor for each frequency measurement.? I would like the replacement to be a dual channel device.

I know that latter versions of HP power meters permit entering correction tables for use with the 848X power sensors.? What would the group recommend?
Some relevant questions:
1) How hard is it to tell the PM what frequency entry to use?
2) Do any of the PMs accept an analog voltage to determine the frequency correction (that would really be fun)
3) Any known problems to look out for

Cheers!

Bruce


Re: How do you decipher HP serial numbers for date.

 

¿ªÔÆÌåÓý

Hi Tom¡­Never heard that part of it before. So who bought the first A models?

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: Thursday, September 01, 2022 11:41 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

And that was in addition to calling it the model 200, with an "A" suffix to boot. Dave Packard was very, very smart.

The model that Disney ended up buying was the 200B, by the way. The 200A was a 35Hz-35kHz unit. Disney wanted that shifted downward, to 20Hz-20kHz. Bill Hewlett made some fast tweaks, and the 200B was shipped off to a happy Disney.

--Cheers,
Tom

-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 9/1/2022 20:35, n8zmTWH@... wrote:

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.

?


Re: How do you decipher HP serial numbers for date.

 

¿ªÔÆÌåÓý

And that was in addition to calling it the model 200, with an "A" suffix to boot. Dave Packard was very, very smart.

The model that Disney ended up buying was the 200B, by the way. The 200A was a 35Hz-35kHz unit. Disney wanted that shifted downward, to 20Hz-20kHz. Bill Hewlett made some fast tweaks, and the 200B was shipped off to a happy Disney.

--Cheers,
Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 9/1/2022 20:35, n8zmTWH@... wrote:

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.



Re: How do you decipher HP serial numbers for date.

 

¿ªÔÆÌåÓý

The story goes that the first HP product was the 200A audio generator. The serial numbers started at 1000 so that their first customer, Disney, wouldn¡¯t think it was the first product they¡¯d ever built and sold. Disney bought 7 of them to use to calibrate the sound for the movie Fantasia.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Jeremy Nichols
Sent: Thursday, September 01, 2022 3:37 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

?

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?

?

?

?

On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:

I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--

Jeremy Nichols
6.


Re: How do you decipher HP serial numbers for date.

 

I¡¯m trying to figure out the serial number of my HP-606A Signal Generator, which is 960-13478. The interpretation I¡¯ve always been told is that this instrument¡¯s design was finalized in the 60th week of 1969! How is that possible??

Another example: my HP-412A carries serial number 0978A19963. 78th week of 1969? A third example: the 3444A DC Multi-function plug-in for my 3440A DVM ?carries serial number 0973A07281. There must be some additional information we¡¯re missing. ?



On Thu, Sep 1, 2022 at 7:29 PM Jim Adney <jadney@...> wrote:
On Thu, Sep 1, 2022 at 12:17 PM, Mikek wrote:
I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285
Looking at your numbers, as well as those of my older HP instruments, it's clear that HP did not start inserting the central letter (country) code right away. It appears that the new scheme that started in 1960 was yww-sssss. It looks like the central country code letter was introduced sometime in '68 or '69, and this may have happened at the same time HP added the leading zero, knowing that 1970 would require it.

It's important to understand that the date, year and week, denotes the date the (new or revised) design was finalized. It's not the build date. It also seems clear that the sequential serial number restarted at 00101 each time the serial prefix (date code) changed. It should also be noted that the serial prefix need not be unique to a particular HP model; it's conceivable that two different design teams could finalize on the same week. As HPs catalog grew, this must have happened often.

There's one (maybe more) exception to this: On HP pocket calculators, the date code IS the year and week of manufacture.

So the design of your 3400A was finalized in the 6th week of 1968, and likewise your 400E was based on the design of week 49 of 1969. If you're looking for a manual for your instrument, it's important to get one that covers your serial prefix. Manuals will often have backdating info as well as update sheets for later instruments. You can look at the serial prefixes for this instrument and bracket the date when yours must have been made.

One of the important things to understand is how many design revisions some of HPs products got. This was especially true of popular instruments which had long production lifetimes like the 200CD, 3400A, and all the various versions of the 400.

--
Jeremy Nichols
6.


Re: How do you decipher HP serial numbers for date.

 

On Thu, Sep 1, 2022 at 12:17 PM, Mikek wrote:
I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285
Looking at your numbers, as well as those of my older HP instruments, it's clear that HP did not start inserting the central letter (country) code right away. It appears that the new scheme that started in 1960 was yww-sssss. It looks like the central country code letter was introduced sometime in '68 or '69, and this may have happened at the same time HP added the leading zero, knowing that 1970 would require it.

It's important to understand that the date, year and week, denotes the date the (new or revised) design was finalized. It's not the build date. It also seems clear that the sequential serial number restarted at 00101 each time the serial prefix (date code) changed. It should also be noted that the serial prefix need not be unique to a particular HP model; it's conceivable that two different design teams could finalize on the same week. As HPs catalog grew, this must have happened often.

There's one (maybe more) exception to this: On HP pocket calculators, the date code IS the year and week of manufacture.

So the design of your 3400A was finalized in the 6th week of 1968, and likewise your 400E was based on the design of week 49 of 1969. If you're looking for a manual for your instrument, it's important to get one that covers your serial prefix. Manuals will often have backdating info as well as update sheets for later instruments. You can look at the serial prefixes for this instrument and bracket the date when yours must have been made.

One of the important things to understand is how many design revisions some of HPs products got. This was especially true of popular instruments which had long production lifetimes like the 200CD, 3400A, and all the various versions of the 400.


Re: How do you decipher HP serial numbers for date.

 

According to this the design date of my 3400A was the 18th week of 1972, built in the good o'l USA and was the 18,284th unit produced. Sweet!


Re: How do you decipher HP serial numbers for date.

 

More historical trivia. I was just looking up something for a member of the VETE (Vintage Electronic Test Equipment) Facebook group and discovered this note regarding the ¡°000-00000¡± (vintage 1960-1970) serial numbers: ¡°If the serial number is prefixed by a letter, the instrument was manufactured outside the United States.¡±



On Thu, Sep 1, 2022 at 12:51 PM Jeremy Nichols via <jn6wfo=[email protected]> wrote:
Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?



On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:
I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--
Jeremy Nichols
6.

--
Jeremy Nichols
6.


Re: Hp 8590a spectrum analyzer

Richard Cook
 

I changed the caps and "to me" it looks good. No fails or anything , I turned corrections off and took some pictures. Maybe I'm overlooking something. I hope not.?


Re: How do you decipher HP serial numbers for date.

 

Trivia: Serial numbers of the form ¡°09mmXnnnnn¡± can also appear as ¡°9mm-nnnnn.¡± Such instruments would have been made in (late, usually) 1969, when the change in format was underway. I suspect this was a practical matter: serial number tags would have been ordered in quantity and in advance of production. Production management, if several hundred of the old serial tags were in stock, would lean towards using up the old ones before bearing the expense of ordering new ones.?



On Thu, Sep 1, 2022 at 10:17 AM Mikek <amdx@...> wrote:
I have two meters both older I know because of the AC plug.

?HP 3400A # 806-08346

HP 400E # 0949A11285

??? Thanks, Mikek

PS, I knew I saw a thread about this, I checked several groups I frequent and couldn't find it.
?
????????????

--
Jeremy Nichols
6.


Re: How do you decipher HP serial numbers for date.

 

Thanks for posting this, Cubdriver. We should understand that this explanation applies primarily to post-1970 instruments and to a slightly lesser extent to instruments made in the 1960s. In particular, the serial number starting with 00101 applied for instruments made in and after 1960. Examination of manuals for instruments made in the 1940s and 1950s shows that serial numbers as low as ¡°1¡± are referenced

Speaking from the perspective of my wife, who worked for HP-Santa Clara (Division 02, the old ¡°Frequency and Time¡± division) for 24 years, new manuals were resisted by middle management, because printing was expensive and the cost came out of their budget. A Change Sheet was much preferred but grew to be a hassle when they grew to number fifty or more (it happened!). Each new instrument was accompanied by the last-printed manual and all of the accumulated change sheets. The customer was expected to go through the change sheets and make changes in the manual himself. This also meant that large numbers of change sheets were not popular with customers who, however, didn¡¯t find out about the change sheets until the instrument was delivered.?



On Thu, Sep 1, 2022 at 9:41 AM Cubdriver <pbmanning@...> wrote:
Hi All -

Back about five years ago, someone who'd worked for HP posted an explanation of the post-1960 serial numbering system, which I then re-posted with my interpretation of it on another forum. Here is a copy of my forum post - the original text is at the start, and my understanding of it follows.

"Copied and pasted from a post to the HPAK mailing list explaining the serial numbering system; the original author worked for HP:

Having worked as a Production Line Engineer, Production Line Manager and Product Support Manager(Americas) for one HP Division, please let me clarify the process for Engineering Changes and how that affects Serial Prefixes.

1. The Basic Identity of an Instrument is the Model No. (e.g. HP 8510A,HP8510B,HP8510C). These Models are all independent of each other and each of the three examples would start with a Serial No.(Suffix) of 00101

2. The most Major Engineering Changes to an Instrument (e.g. Addition of a bunch of New Features or Upgrades) could be implemented into a New Model No. (e.g. change from "A" model to "B" model). In the case of changing to a New Model No. the Serial No.(Suffix) will start again at 00101.

Short of a New Model No., all other changes would be handled through a "Production Change Order".

3. A Production Change Order may or may not trigger a New Serial Prefix. Typically, for instance, the change of a single component value would not cause a Serial Prefix change. I believe (but I'm not 100% on this), that would be decided by Production Engineer in conjunction with Product Support folks, who are responsible for Service Manuals. Major Engineering Changes would always trigger a New Prefix.

4. Instrument Manufacturing is done in Batches, called Production Runs. The Size of each Run is determined by Sales Volume. More Sales, Larger Runs.

5. A New Serial Prefix would be implemented for the Start of a New Production Run. Before issuing Work Orders for a New Production Run, I believe a review of Engineering Change Level would be done and the decision to introduce a New Prefix would be made or had already been made. That could be due to one Major change or sometimes a roll-up of a bunch of Minor ones.

Keep in mind none of this is instantaneous, 'cos of lead times for (new)material to be provisioned.

6. In an Emergency (quite rare), it has been known for a Production Change to be implemented immediately, maybe 'cos of a Safety concern(I did it only once) or some major Defect being discovered.

7. I think by now it has been well established that the Serial Prefix first two digits are the number of Years since 1960 and the last two are the week number of the last Production change included in the Instrument.

Sorry for being a bit Verbose, but that's how it works.

Paraphrasing my understanding of the above:

1: The model number and its letter suffix identifies the instrument type. Each is considered to be independent of the others for serial numbering purposes, and starts with a 00101 serial number suffix.

2: An expansion of (1) reiterating that the serial number resets with a new letter revision to an instrument when major changes are made. If it is only a rev change then the serial number will continue to increment sequentially from the last instrument made under the previous engineering rev.

3: Minor changes would not trigger a prefix update; more major ones (but those that were not enough to trigger a new model suffix revision) would trigger a prefix update.

4: When a design is released, they build a bunch at a time.

5: This one hung me up for a bit until I thought it through a bit more and paid attention to the wording. A new serial prefix would be implemented at the start of a new production run (note that it's 'would be', not 'will be' or 'is' - it only changes if the design is revised) Prior to the new run, they'd look everything over, and determine if a new prefix was needed; if it was not then the new run would get the old (but current to the design, as it's essentially unchanged) prefix.

To summarize my understanding of what 2-5 mean, for example, if the last unit of the run of the mythical HP 0000A Whatsis (introduced in the 32nd week of 1972) serial number 1232A00250 is finished and the design undergoes a major change to become an HP 0000B Whatsis in the second week of January, 1975, then the first new HP 0000B off the line will be serial number 1502A00101 (new prefix, reset serial). If, instead, the new iteration of the HP 0000A comes off the assembly line with a lesser engineering change (not enough to warrant it becoming a 'B' model), then the first unit in the new run will have a serial number of 1502A00251 (new prefix, incremented serial). If it's just a new run with no real changes, then the first off the line in January of 1975 would be serial number 1232A00251 (old prefix, incremented serial).

6 & 7: self explanatory.

I left the OP's name off because it was posted to the mailing list; if anyone wants to dig it was posted on 10/05/17."

-Pat






> ------ Original Message ------
> From: jn6wfo@...
> To: [email protected]
> Sent: Thursday, September 1, 2022 10:32 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] How do you decipher HP serial numbers for date.

Actually, Matt¡¯s serial number ID (mmmmXnnnnn where X is the country of manufacture) applies to designs (redesigns) finalized in or after 1970.
A=America (USA), G=Germany, J=Japan, U=United Kingdom, etc.

For 1960-1969, the serial number is of the form nnn-mmmm where the first part is the date code and the second part the series number. The first digit in the date code is added to 1960 to give the year. The second two digits are often said to be a week number but I¡¯ve seen numbers higher than 52 so I¡¯m unsure. For instruments with small unit runs, the serial number block is sometimes shared with other instruments.

For instruments before 1960, there¡¯s a simple serial number that has no date significance. Numbers range from 1 to 5 digits; comparing the various versions of the manuals and catalogs, if you can find them, can give a rough idea of the date.


On Thu, Sep 1, 2022 at 5:52 AM Matt Huszagh <huszaghmatt@...> wrote:
The serial number consists of a 4-digit date code followed by a letter indicating the country of manufacture, followed by a sequence of digits that uniquely identifies the instrument.

In the 4-digit date code, the first two digits are the number of years since 1960 and the last two digits are the number of weeks into the year. This date code represents the date of design, not manufacture. It¡¯s a common misconception that this means build date. It doesn¡¯t.

For the country code, off memory, A is USA, J is Japan, M Malaysia. Probably others too. I think this indicates location of manufacture rather than design, but I could be wrong on that.

I think the 5-digit suffix is sequentially assigned based on build date, but I don¡¯t know.

So, to answer your question you can¡¯t really know when your instrument was built other than it was sometime after the date code. Previously, I expect HP would have been able to provide this information if you called in, but I doubt keysight would (or probably even could) tell you that anymore. But you could try.

FYI this question has been posed and answered a number of times before. A search on the HP-Agilent-Keysight group would yield the same info. The serial number format is also usually described at the beginning of instrument manuals.

Matt

--
Jeremy Nichols
6.



--
Jeremy Nichols
6.