Hi Bruce,
Yes, guess its a desire/price issue... :)
Anybody wanting to try the script, and having issues, let me know.
Regards, Askild
On Fri, Sep 2, 2022 at 10:10 PM Bruce < bruce@...> wrote: Askid -
Thanks.? Yes, I looked over the 437 and noted the lack on numeric?
keys.? I may take you up on the script if I decide to get a 437.? To?
me it looks like the E series are still too expensive.? I'll just keep?
my eyes open and see what pops up.
Cheers!
Bruce
Quoting Askild <megafluffy@...>:
> Hi Bruce,
>
> The 437B is of course only a single channel power meter, so if you want
> dual upgrade from the 438A you will need to go to the E-series.
> I have a 437B, and it suits my needs for a power meter. I also have a 432A,
> a 435B, and almost a 436A (Its missing the A2, A3, A4 and A5 boards. So if
> anybody want to donate, please let me know :)
>
> I made two simple python scripts to read from, and write cal tables to the
> 437B. Much easier to enter the cal table into a text editor, than using the
> arrow keys.
>
> The biggest drawback on the 437B is the lack of number keys. All entries
> are adjusted with arrow keys, But its easier to just set the frequency,
> than figuring out the correct cal factor and enter that.
>
>
> Regards,
> Askild
>
>
> On Fri, Sep 2, 2022 at 8:43 PM Bruce <bruce@...> wrote:
>
>> Dave - Thanks.
>>
>> I didn't think to take a look at the 437 and I did assume that the 438
>> was an upgrade on the 437 - wrong I guess.? I really do like my 438s
>> except for the inconvenience of entering the cal factor each time.
>>
>> Cheers!
>>
>> Bruce
>>
>> Quoting Dave McGuire <mcguire@...>:
>>
>> > On 9/1/22 23:45, Bruce wrote:
>> >> 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
>> >
>> >? ?The E4417/E4418 power meters have come down in price, and are very
>> > nice.? They will also use the later series of sensor heads that
>> > store the calibration factors in an EEPROM in the head, which are
>> > read out by the meter and applied.? You can also use the more common
>> > 84xx heads that only have the calibration factors printed on them,
>> > not stored within them, and you enter the table manually into the
>> > meter's NVRAM.? Then you select the measurement frequency and it
>> > will apply the calibration factor automatically, with interpolation.
>> >
>> >? ?The 437B cannot read the calibration factor table from the newer
>> > sensor heads, but you can enter the table via the front panel or
>> > GPIB. It can store ten tables for ten different sensors.
>> >
>> >? ?My main bench instrument now is an E4417A, which I really like.
>> > The display is excellent; in some modes it will display LARGE digits
>> > which you can read across a room.
>> >
>> >? ?For years I used a 437B, which I still have and use occasionally
>> > in another area.? Everyone complains about the display, I don't have
>> > a problem with it myself, I just don't try to use it in the dark.
>> > The design shares many attributes (and possibly components) with the
>> > 5384/5385 frequency counters, 3468/3478 DMMs, etc, so if you have
>> > one of those, you know what the display is like.
>> >
>> >? ?I've not looked it up, but I'm willing to bet the 437B was
>> > designed well after the 438A.? While I think the 438A is a fine
>> > design in nearly all respects, everything about it seems older than
>> > the 437B.? Older display and button styles, less-featureful firmware
>> > (lack of sensor calibration table storage and interpolation) etc.
>> >
>> >? ?I've never seen a feature by which an analog input voltage can set
>> > the correction factor.
>> >
>> >? ?I have every model of HP RF power meter, including the VXI and MSS
>> > models.? If you'd like specific info on behaviors/features/etc on
>> > any of them that aren't covered by the documentation, don't hesitate
>> > to ask.
>> >
>> >? ? ? ? ? ? ? -Dave
>> >
>> > --
>> > Dave McGuire, AK4HZ
>> > New Kensington, PA
>> >
>> >
>> >
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
|
Re: How do you decipher HP serial numbers for date.
Don -
That sounds a lot like the 200As that I used at UW in 1962.
Actually wouldn't suprise me if they (UW) still had a few floating around. I also remember a black cased version.
Cheers!
Bruce
Quoting "Don Bitters via groups.io" <donbitters@...>:
toggle quoted message
Show quoted text
I have actually seen a HP 200A model. It was not in a standard case for the slightly later time period (think HP 540A counter) - the type that the 200C was cased in.? It was in a larger case similar to the 200B, but all of the corners were square and the front panel mounting screws were on the face. The entire unit was a uniform medium grey with white or black markings - I cannot remember which.? I might have seen it at one of the factories or at HP Palo Alto, many, many years ago (1970's).
Don Bitters
|
Askid -
Thanks. Yes, I looked over the 437 and noted the lack on numeric keys. I may take you up on the script if I decide to get a 437. To me it looks like the E series are still too expensive. I'll just keep my eyes open and see what pops up.
Cheers!
Bruce
Quoting Askild <megafluffy@...>:
toggle quoted message
Show quoted text
Hi Bruce,
The 437B is of course only a single channel power meter, so if you want
dual upgrade from the 438A you will need to go to the E-series.
I have a 437B, and it suits my needs for a power meter. I also have a 432A,
a 435B, and almost a 436A (Its missing the A2, A3, A4 and A5 boards. So if
anybody want to donate, please let me know :)
I made two simple python scripts to read from, and write cal tables to the
437B. Much easier to enter the cal table into a text editor, than using the
arrow keys.
The biggest drawback on the 437B is the lack of number keys. All entries
are adjusted with arrow keys, But its easier to just set the frequency,
than figuring out the correct cal factor and enter that.
Regards,
Askild
On Fri, Sep 2, 2022 at 8:43 PM Bruce <bruce@...> wrote:
Dave - Thanks.
I didn't think to take a look at the 437 and I did assume that the 438
was an upgrade on the 437 - wrong I guess. I really do like my 438s
except for the inconvenience of entering the cal factor each time.
Cheers!
Bruce
Quoting Dave McGuire <mcguire@...>:
On 9/1/22 23:45, Bruce wrote:
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 The E4417/E4418 power meters have come down in price, and are very
nice. They will also use the later series of sensor heads that
store the calibration factors in an EEPROM in the head, which are
read out by the meter and applied. You can also use the more common
84xx heads that only have the calibration factors printed on them,
not stored within them, and you enter the table manually into the
meter's NVRAM. Then you select the measurement frequency and it
will apply the calibration factor automatically, with interpolation.
The 437B cannot read the calibration factor table from the newer
sensor heads, but you can enter the table via the front panel or
GPIB. It can store ten tables for ten different sensors.
My main bench instrument now is an E4417A, which I really like.
The display is excellent; in some modes it will display LARGE digits
which you can read across a room.
For years I used a 437B, which I still have and use occasionally
in another area. Everyone complains about the display, I don't have
a problem with it myself, I just don't try to use it in the dark.
The design shares many attributes (and possibly components) with the
5384/5385 frequency counters, 3468/3478 DMMs, etc, so if you have
one of those, you know what the display is like.
I've not looked it up, but I'm willing to bet the 437B was
designed well after the 438A. While I think the 438A is a fine
design in nearly all respects, everything about it seems older than
the 437B. Older display and button styles, less-featureful firmware
(lack of sensor calibration table storage and interpolation) etc.
I've never seen a feature by which an analog input voltage can set
the correction factor.
I have every model of HP RF power meter, including the VXI and MSS
models. If you'd like specific info on behaviors/features/etc on
any of them that aren't covered by the documentation, don't hesitate
to ask.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Hi Bruce,
The 437B is of course only a single channel power meter, so if you want dual upgrade from the 438A you will need to go to the E-series. I have a 437B, and it suits my needs for a power meter. I also have a 432A, a 435B, and almost a 436A (Its missing the A2, A3, A4 and A5 boards. So if anybody want to donate, please let me know :)
I made two simple python scripts to read from, and write cal tables to the 437B. Much easier to enter the cal table into a text editor, than using the arrow keys. The biggest drawback on the 437B is the lack of number keys. All entries are adjusted with arrow keys, But its easier to just set the frequency, than figuring out the correct cal factor and enter that.
Regards, Askild
On Fri, Sep 2, 2022 at 8:43 PM Bruce < bruce@...> wrote: Dave - Thanks.
I didn't think to take a look at the 437 and I did assume that the 438?
was an upgrade on the 437 - wrong I guess.? I really do like my 438s?
except for the inconvenience of entering the cal factor each time.
Cheers!
Bruce
Quoting Dave McGuire <mcguire@...>:
> On 9/1/22 23:45, Bruce wrote:
>> 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
>
>? ?The E4417/E4418 power meters have come down in price, and are very?
> nice.? They will also use the later series of sensor heads that?
> store the calibration factors in an EEPROM in the head, which are?
> read out by the meter and applied.? You can also use the more common?
> 84xx heads that only have the calibration factors printed on them,?
> not stored within them, and you enter the table manually into the?
> meter's NVRAM.? Then you select the measurement frequency and it?
> will apply the calibration factor automatically, with interpolation.
>
>? ?The 437B cannot read the calibration factor table from the newer?
> sensor heads, but you can enter the table via the front panel or?
> GPIB. It can store ten tables for ten different sensors.
>
>? ?My main bench instrument now is an E4417A, which I really like.? ?
> The display is excellent; in some modes it will display LARGE digits?
> which you can read across a room.
>
>? ?For years I used a 437B, which I still have and use occasionally?
> in another area.? Everyone complains about the display, I don't have?
> a problem with it myself, I just don't try to use it in the dark.? ?
> The design shares many attributes (and possibly components) with the?
> 5384/5385 frequency counters, 3468/3478 DMMs, etc, so if you have?
> one of those, you know what the display is like.
>
>? ?I've not looked it up, but I'm willing to bet the 437B was?
> designed well after the 438A.? While I think the 438A is a fine?
> design in nearly all respects, everything about it seems older than?
> the 437B.? Older display and button styles, less-featureful firmware?
> (lack of sensor calibration table storage and interpolation) etc.
>
>? ?I've never seen a feature by which an analog input voltage can set?
> the correction factor.
>
>? ?I have every model of HP RF power meter, including the VXI and MSS?
> models.? If you'd like specific info on behaviors/features/etc on?
> any of them that aren't covered by the documentation, don't hesitate?
> to ask.
>
>? ? ? ? ? ? ? -Dave
>
> --
> Dave McGuire, AK4HZ
> New Kensington, PA
>
>
>
|
Re: How do you decipher HP serial numbers for date.
Ken,
Thanks for the comment. The date of my 606A is not in question, only the serial number prefix, which seems to suggest an ¡°impossible¡± week (60th week of 1969).?
Greetings,
FWIW the 606A/B is listed in the 1967 HP catalog.? Some of the schematics in my 606 manual show a copyright of 1965.
Regards,
Ken
On 1Sep, 2022, at 9:07 PM, Jeremy Nichols < jn6wfo@...> wrote:
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.
I have actually seen a HP 200A model. It was not in a standard case for the slightly later time period (think HP 540A counter) - the type that the 200C was cased in.? It was in a larger case similar to the 200B, but all of the corners were square and the front panel mounting screws were on the face. The entire unit was a uniform medium grey with white or black markings - I cannot remember which.? I might have seen it at one of the factories or at HP Palo Alto, many, many years ago (1970's).
Don Bitters
|
Freudian slip?
In Agilent product note 894400-2, for the 89400 (which may already have a typo in its title, but that's the title of the document), on page 3, the caption for Figure 2 is "Agilent channel power". It should be "adjacent channel power".
I got a chuckle out of it. :)
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Matt -
That would be TWO of us - but the 438 does not provide table entry.
Cheers!
Bruce
Quoting Matt Huszagh <huszaghmatt@...>:
toggle quoted message
Show quoted text
Does the 438 not permit you to store sensor cal factor tables? The 437
supports this and you can simply enter the frequency; the 437 will then
choose the corresponding cal factor or interpolate as needed. I always
thought of the 438 as a two-channel upgrade to the 437.
I'm a bit surprised HP wouldn't have incorporated this pretty basic feature
into the 438.
Matt
|
Dave - Thanks.
I didn't think to take a look at the 437 and I did assume that the 438 was an upgrade on the 437 - wrong I guess. I really do like my 438s except for the inconvenience of entering the cal factor each time.
Cheers!
Bruce
Quoting Dave McGuire <mcguire@...>:
toggle quoted message
Show quoted text
On 9/1/22 23:45, Bruce wrote:
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 The E4417/E4418 power meters have come down in price, and are very nice. They will also use the later series of sensor heads that store the calibration factors in an EEPROM in the head, which are read out by the meter and applied. You can also use the more common 84xx heads that only have the calibration factors printed on them, not stored within them, and you enter the table manually into the meter's NVRAM. Then you select the measurement frequency and it will apply the calibration factor automatically, with interpolation.
The 437B cannot read the calibration factor table from the newer sensor heads, but you can enter the table via the front panel or GPIB. It can store ten tables for ten different sensors.
My main bench instrument now is an E4417A, which I really like. The display is excellent; in some modes it will display LARGE digits which you can read across a room.
For years I used a 437B, which I still have and use occasionally in another area. Everyone complains about the display, I don't have a problem with it myself, I just don't try to use it in the dark. The design shares many attributes (and possibly components) with the 5384/5385 frequency counters, 3468/3478 DMMs, etc, so if you have one of those, you know what the display is like.
I've not looked it up, but I'm willing to bet the 437B was designed well after the 438A. While I think the 438A is a fine design in nearly all respects, everything about it seems older than the 437B. Older display and button styles, less-featureful firmware (lack of sensor calibration table storage and interpolation) etc.
I've never seen a feature by which an analog input voltage can set the correction factor.
I have every model of HP RF power meter, including the VXI and MSS models. If you'd like specific info on behaviors/features/etc on any of them that aren't covered by the documentation, don't hesitate to ask.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Re: How do you decipher HP serial numbers for date.
On Thu, Sep 1, 2022, 05:54 Mikek < amdx@...> wrote: I recently bought an HP 3400A, and want to get a build date and also find the proper schematic for repair.
?Is there a site that tells how to decipher the serial number?
For most HP instruments (pre 2000), the serial number doesn't tell you the build date. The first four digits are YY and WW, where YY is the number of years since 1960 and WW is the week. However, that's not when it was built; that's the production series. During production they only updated the YYWW when there was a significant production change, requiring updated information or procedures in the service manual.
Corvallis Division (calculators) and some 1980s+ computer stuff are exceptions, where due to high production volume, they actually update YYWW every week rather than only in changes. AFAIK, that was not done on any HP instruments during the lifetime of that serial number scheme. With Agilent and Keysight things changed.
|
Re: How do you decipher HP serial numbers for date.
Greetings,
FWIW the 606A/B is listed in the 1967 HP catalog. ?Some of the schematics in my 606 manual show a copyright of 1965.
Regards,
Ken
toggle quoted message
Show quoted text
On 1Sep, 2022, at 9:07 PM, Jeremy Nichols < jn6wfo@...> wrote:
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.
|
On 9/2/22 08:51, John Griessen wrote: So when you want two powers readable at the same time nevermind... Your fave the E4417A does two channels...
|
On 9/2/22 08:30, Dave McGuire wrote: ? I have every model of HP RF power meter, including the VXI and MSS models. So when you want two powers readable at the same time, do you use two E4417/E4418 power meters?
|
On 9/2/22 09:47, Matt Huszagh wrote: Does the 438 not permit you to store sensor cal factor tables? The 437 supports this and you can simply enter the frequency; the 437 will then choose the corresponding cal factor or interpolate as needed. I always thought of the 438 as a two-channel upgrade to the 437.
I'm a bit surprised HP wouldn't have incorporated this pretty basic feature into the 438. See my previous email on this; I don't know for sure but I'm willing to bet that the 438 was not the successor to the 437. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
On 9/1/22 23:45, Bruce wrote: 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 The E4417/E4418 power meters have come down in price, and are very nice. They will also use the later series of sensor heads that store the calibration factors in an EEPROM in the head, which are read out by the meter and applied. You can also use the more common 84xx heads that only have the calibration factors printed on them, not stored within them, and you enter the table manually into the meter's NVRAM. Then you select the measurement frequency and it will apply the calibration factor automatically, with interpolation. The 437B cannot read the calibration factor table from the newer sensor heads, but you can enter the table via the front panel or GPIB. It can store ten tables for ten different sensors. My main bench instrument now is an E4417A, which I really like. The display is excellent; in some modes it will display LARGE digits which you can read across a room. For years I used a 437B, which I still have and use occasionally in another area. Everyone complains about the display, I don't have a problem with it myself, I just don't try to use it in the dark. The design shares many attributes (and possibly components) with the 5384/5385 frequency counters, 3468/3478 DMMs, etc, so if you have one of those, you know what the display is like. I've not looked it up, but I'm willing to bet the 437B was designed well after the 438A. While I think the 438A is a fine design in nearly all respects, everything about it seems older than the 437B. Older display and button styles, less-featureful firmware (lack of sensor calibration table storage and interpolation) etc. I've never seen a feature by which an analog input voltage can set the correction factor. I have every model of HP RF power meter, including the VXI and MSS models. If you'd like specific info on behaviors/features/etc on any of them that aren't covered by the documentation, don't hesitate to ask. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
The 438A does not provide a way to store a cal factor and corresponding frequency for recall at a later time - This also means that it won't do the cal factor estimation for frequencies between cal factor points.
That was one of the reasons that I kept my 437 until I was able to move to an E4418B - I keep a 438A around for those times when I need a dual channel and just live with the need to enter the factors when measuring.
TonyG
|
Does the 438 not permit you to store sensor cal factor tables? The 437 supports this and you can simply enter the frequency; the 437 will then choose the corresponding cal factor or interpolate as needed. I always thought of the 438 as a two-channel upgrade to the 437.
I'm a bit surprised HP wouldn't have incorporated this pretty basic feature into the 438.
Matt
|
Re: How do you decipher HP serial numbers for date.
On Fri, Sep 2, 2022 at 05:25 AM, Adrian Godwin wrote:
> 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
I'm the one who went out on a limb with that statement. I don't have any direct knowledge of this; my understanding is based on an email conversation I had with the owners of . I had emailed them to try to explain how I thought the HP serial prefix coded the year and week of design finalization, and they claimed that this was not true in the case of handheld HP calculators. I took their word for it. It seems quite possible that early calculator production followed the established HP pattern, but later production might have changed. Your HP-35s are quite early, while mine are much later. But both of mine share a common serial prefix, 1346A. I agree that the sequential numbers, 12108 &?15956, seem too high for one week's production. OTOH, I have two HP-45s, with serial prefixes that differ by 1: 1349A and 1350A. The sequential serial numbers, 16002 &?34910, make me wonder if the prefix changed but the sequential serial numbers continued uninterrupted. Does anyone know how many calculators HP could produce in a week? Bonus question: What 3 key combination press does what on an HP-35? Likewise for the HP-45? (Note: it takes practice to be able to depress all 3 keys at exactly the same time.)
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I never knew about this model.? I have been using the 436A and bought a 437A which I believe can have the Cal factors entered, but I don't like the LCD display so do not use it.? Why did HP make the 438A with LED display?? Is it newer than the 437A?
On Thu, Sep 1, 2022 at 11:45 PM Bruce < bruce@...> wrote: 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
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Re: How do you decipher HP serial numbers for date.
Most of my collection has numbers below ¡°52,¡± so I agree the larger numbers are rare.?
Also note that all of my examples are 1969 ¡°models.¡± I wonder if HP went with your ¡°Possibility A¡± in order to keep the old serial number format for stuff started in 1969??
On Fri, Sep 2, 2022 at 5:06 AM Jim Adney < jadney@...> wrote: 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.?
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Jeremy Nichols
Dave McGuire