Agilent / HP serial number confusion

[PTR_1275]

Hi everyone,

I know you can date a HP product based on the serial number and from my memory it was 1963 plus the first 2 digits gave you the year of manufacture.

Looking around to confirm this, everything I have found is saying 1960.

I have a 6050a load bank that is 2940axxxxx indicating 1989 manufacture if it’s based on 1960 + 29 (then week 40)

The IC’s on the main board are mostly mid 90 date codes, the newest one I can see is 9113, so this doesn’t make sense if the unit was made in ‘89.

Do you think the main board has been replaced at some point, or am I off on the serial number decoding?

[0culus]

The first two digits are years since 1960, not 1963.

[bitseeker]

I know you can date a HP product based on the serial number

You can't date the product exactly. The first 2 digits + 1960 gives you the year of the design that the product is based on. It could've been manufactured in that year or any year thereafter until the next design change.

and from my memory it was 1963 plus the first 2 digits gave you the year of manufacture.

Looking around to confirm this, everything I have found is saying 1960.

It is 1960.

I have a 6050a load bank that is 2940axxxxx ... The IC’s on the main board are mostly mid 90 date codes, the newest one I can see is 9113, so this doesn’t make sense if the unit was made in ‘89.

It makes sense that the components would be dated after late 1989.

Also note that the 'A' in the serial number means it was made in the USA (colloquially, 'A' for "America").

[PTR_1275]

Ahhhh, the design is from that date, that makes sense.

I thought it was the date of manufacture.

At lunch I was reading through Tin’s 3245a repair writeup and noticed that had a serial number indicating 89 date, but components inside were 91 as well.


Thanks for that bit of information that I was missing

[bitseeker]

It's a common misconception and the HP manuals don't explain it (at least the ones I've seen don't). They just say that the first two digits plus 1960 refers to the year, but not the year of what. Supposedly, it may have been printed somewhere official, sometime long ago, but I have yet to find it.

[dzseki]

I have a HP 1720A scope that was introduced in some of the 1974's HP Journal, but the serial number starts with 1722A, and the internals are line up with that as well.
I also have a HP 1120A FET probe for the scope which was introduced in some of the 1969's HP Journal, yet the serial number starts with 2311A, and again the internal component's date codes align to this.
Does the revision count as design date? 

[bitseeker]

A product's design can be updated several times during the model's life. Sometimes the changes are obvious, other times less so. Sometimes the model's letter suffix changes, and other times it doesn't. I'm not sure how significant a change had to be to be reflected in the model designation.

[Stray Electron]

   For some of HP's products they order the labels in batches so every machine that got a label from that batch will have the same datecode.  IIRC there were only two of labels for the HP 35 calculator so all HPs 35 have one of only two different date codes.  I've noticed the same on some of their German made products.

   A board level repair at some point could also account for a piece of gear having many ICs with date codes later than the equipment itself.