Re: [volt-nuts] What's the probability of a random used 3458A passing a Keysight calibration?

[J. L. Trantham]

I think the only option for repair, out of warranty or out of repair agreement, 
is 'Per Incident' which the KS website lists as $2851.00.  This is a 'one 
charge fits all' kind of repair price.  It comes with a calibration as well.

It's what makes the repair agreement attractive as 'insurance' on such an 
expensive instrument.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Dr. David 
Kirkby
Sent: Tuesday, January 16, 2018 5:35 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] What's the probability of a random used 3458A passing 
a Keysight calibration?

On 16 January 2018 at 23:06, Dr. Frank  wrote:

> Surely the AC errors if any must be associated with the A2 AC 
> Convertor
>>> board - 03458-66502?  >> Dave
>>>
>>
> Why should this be a hardware error???
>
> It's much much more probable, that this is a natural drift phenomenon.
> This is 'as found' and the 'as left' report is missing, that would 
> tell the whole story.
>
> Anyhow, this can very probably be adjusted by the regular calibration 
> process.
>
> Frank
>


But given that Keysight calibration includes adjustments free of charge, the 
fact it was not adjusted suggests that it can not be adjusted. The AC board 
03458-66502 is obsolete, but the replacement (03458-66512)

https://www.keysight.com/my/faces/partDetail.jspx?partNumber=03458-66512

is $2243.00with a $439 trade-in. So the AC board price is $1794, which is not 
inconsistent with a 2100 Euro repair bill.

Dave
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Re: [volt-nuts] What's the probability of a random used 3458A passing a Keysight calibration?

[J. L. Trantham]

Forgot to add.  All were purchased on theBay.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of J. L. Trantham
Sent: Monday, January 15, 2018 9:12 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] What's the probability of a random used 3458A passing 
a Keysight calibration?

Dave,

I have three of these meters that have all been sent to Agilent/Keysight for 
the 'Agilent/Keysight' Calibration and all have passed.  Two of the three were 
still 'in spec' when arrived.  The third lost its calibration when I failed to 
properly remove the 'CalRam' and read it.  I think I tried to read it when 
still 'hot' from the removal process.  There is a process that you can use via 
HPIB to read the contents of the CalRam but I did not know about it at the 
time.  I wanted to remove the chip, install a socket and install a new chip 
before I sent it back to Agilent/Keysight.

I had previously sent a Solartron 7081 to Ametek in England for calibration and 
I used it to provide a 'transfer standard' to do my own 'in house' 
recalibration of that 3458A and it was 'in spec' in all ranges when it went 
back to Agilent, except a couple of the AC voltage ranges.  However, it was 
able to be successfully 'recalibrated' and was 'in spec' on its next trip for 
recalibration.  That was at a time when the calibrations were done in Loveland.

Once a 3458A has passed it's 'recalibration', you can purchase the 'Repair 
Agreement' for $192 per year with up to 5 years at a time (for a slight 
discount) that will allow you to send it back to Keysight for repair and 
recalibration for 'no charge' other than the cost of the 'Repair Agreement' if 
it ever fails during the covered time frame.

Hope this helps.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Dr. David 
Kirkby
Sent: Monday, January 15, 2018 3:56 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] What's the probability of a random used 3458A passing a 
Keysight calibration?

There's an "interesting" $5400 buy-it-now on eBay at the minute. It's described 
as "Agilent 3458A 8.5 digit Multimeter CALIBRATED".

http://www.ebay.co.uk/itm/Agilent-3458A-8-5-Digit-Multimeter-CALIBRATED/
232593692038

When one reads the description, one can see it is an HP (not Agilent) 3458A, 
that was sent to Keysight for calibration, but *failed* on the 3 V 4 MHz AC 
voltage. Apparently it passed on everything else. Personally I would sell that 
as "spares or repair" rather than "used" and "CALIBRATED", but different people 
have different ideas of what is good or not.

Out of interest, I asked the seller what Keysight had quoted to repair this. He 
said 2100 Euros, (which about $2600 USD or £1900 GBP). So to get it in shape, 
it is not exactly peanuts.

The seller said to me that he has a *lot* of experience of 3458As, and knows 
that a used one has less than a 50% chance of passing a Keysight calibration. I 
wonder if that's the experience of others that have bought used 3458As and sent 
them to Keysight. If true, and I ever buy a 3458A, I think I would only buy one 
on the condition that the seller  sends it to Keysight, I pay the calibration 
cost, but if it fails, I get a full refund, including the calibration cost.

I can understand a meter going out of spec over time, but if it can't be sorted 
out without thousands of dollars spent on it, then it is not such a good buy. 
But are more than 50% of 3458As like this?

Dave


Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT, 
United Kingdom Registered in England and Wales as company number 08914892 
http://www.kirkbymicrowave.co.uk/ Tel 01621'680100 / +44 1621-680100 
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Re: [volt-nuts] Solartron 7081 randomly re-initialises

[J. L. Trantham]

David,

I have had a similar issue with mine but only on days when my stand-by 
generator turns on, takes the load for the house, then switches the load back 
to the street and shuts down.  There is clearly a brief 'power hit' when this 
occurs.  I've never tried to chase this down because it is relatively 'rare'.

There is a fairly 'complex' shut-down circuitry in the 7081 described in the 
service manual and I wonder if you have an issue there.

In any event, I suspect a 'power issue'.

Good luck.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. 
Partridge
Sent: Thursday, April 14, 2016 6:09 AM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081 randomly re-initialises

That makes sense though +5V looked OK, I'll look a bit harder!

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of acb...@gmx.de
Sent: 14 April 2016 11:26
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Solartron 7081 randomly re-initialises

guestimate, executes a cold start caused by low voltage. 
so would check 5V for drops and ripple.
keep us posted on your findings


> Gesendet: Donnerstag, 14. April 2016 um 11:45 Uhr
> Von: "David C. Partridge" 
> An: "'Discussion of precise voltage measurement'" 
> , solartron_schlumberger_equipm...@groups.io
> Betreff: [volt-nuts] Solartron 7081 randomly re-initialises
>
> One of my 7081s will occasionally re-start from running in TRACK mode, 
> ending up with the INITIALIZED message on the display.
> 
>  
> 
> Does anyone have any thoughts as to likely faults that would cause this?
> 
>  
> 
> Dave
> 
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Re: [volt-nuts] HP-3458A questions

[J. L. Trantham]

Frank,

Thanks for the picture of your board.  

I have been interested in the 'plastic cap' on the LTZ1000A and you provided me 
with information about this in the past.

Do you have a picture of the bottom of the board?  I would love to see how the 
bottom half of the 'cap' looks.

Thanks.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Frank Stellmach
Sent: Tuesday, June 02, 2015 4:50 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] HP-3458A questions

Hi Randy,

in advance, this change only improves the stability of the instrument, when the 
3458A is powered.
The LTZ1000 will not age (nearly), when the instrument is switched off.
Therefore, it makes sense mainly, if your instrument is running for an extended 
period of time.

(Reference: Spreadbury: Ultra Zener..)

If you change the oven temperature, you will loose the 10V calibration, as the 
LTZ1000A will change its reference voltage.


Although my instrument is strictly switched off, when not doing 
measurements, I reduced the oven temp. by connecting a 100k precision 
wirewound (3ppm/K) in parallel to the 15k BMF resistor. That gives 13k 
in total, yielding about 65°C like in the LT datasheet.
An alternative placement is already foreseen on the PCB; in the CLIP, 
it's component designator is X411.
I'll try to link in a photo of my change.

lymex on the bbs35.hot forum obviously was more agressive, and paralled 
75k of Vitrohm Thin Film, giving 12.5k for about 55°C.

I would recommend my solution above the one of lymex, although his one 
gives theoretically more stability.
Also, the lower stability of TF reistors may affect the stability (T, t) 
of the 15k BMF.

With 100k/65°C, the oven runs about 30°C lower.
Therefore, the ambient temperature has to be limited to max. 35°C, the 
fan has ALWAYS to be kept clean, giving a maximum temperature rise of 
15°C, and the instrument may not be put in a rack (which would give 
additional 10..20°C temperature rise). Under these conditions, (35°C 
ambient + 15°C 3458A inner heating + 10°C self heating of LTZ1000A + 5°C 
regulation margin), the oven will always be stable.

These 75k / 55°C would be possible, only if you limit the ambient 
temperature further, to = 25°C, and precisely monitor the 3458A inner 
temperature (TEMP?).

Although my instrument is kept at 20..23°C throughout the year, i 
wouldn't feel comfortable with 55°C.
The only possibility would be the exchange of the reference to the non-A 
version, as the self heating effect may vanish!

Frank

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Re: [volt-nuts] Fluke 731B

[J. L. Trantham]

John,

Thanks for the thoughts.  I basically agree with the idea of not 'adjusting' 
the standards but when I got them, they all had 'problems', including leaking 
NiCd batteries that required clean up.  Not knowing how long they had been off 
and having only calibrated DMM's (3458A and 7081) I chose to get the standards 
up and running then 'adjust' them to begin a 'new era' of standards, at least 
in my set-up.

I also have two 732A's that have been brought back to life and they are sitting 
on now for about 12 to 18 months.  I have not tried to read them in a while.

I have been collecting other gear including Fluke 720A, 721A, 750A, and 752A 
and a Fluke 845AB.  I also have a Fluke 887AB that I need to get working.  My 
problem is that work is about 80 to 100 hours per week and I have little time 
to spend on this.  But, once retired.

I have left my 3458A's on for extended periods of time (weeks) and have been 
very pleased that when I turn them back on after weeks off, they come back 
within a couple of uV to the last readings of the 735C suggesting everything is 
fairly stable or at least drifting at the same rate and in the same direction.

I'm a bit nervous about leaving the 3458A's on all the time due to the 
potential for the displays to fade or fail.  So far, that's not been a problem.

As far as calibration of the Fluke references, I would think Fluke would be the 
best bet but there is the problem of getting them there and back while still 
powered.  I've been working on a method to do that using SLA batteries or using 
the Fluke 732A-7003 battery charger/pack.  I think Fluke made a case that would 
house the 732A and the 732A-7003, both filled with batteries and completely 
charged, to ship the units in for calibration.  My plan is to construct a 
'case' to house two 12V 18AH SLA's and a charger that can be plugged in once 
the unit arrives at the calibration facility.

I have acquired a couple of dead, industrial strength, UPS's that, once I get 
some time, I would like to rebuild and power my 'metrology section' with to 
deal with any power interruptions.  I have a stand-by generator system as well. 
 However, it all takes time to get up and running and I don't have much of that 
right now.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips
Sent: Friday, March 27, 2015 1:41 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 731B

I would never adjust any pots on a working fluke voltage standard. When the pot 
moves you introduce more drift.
Just keep track of differences.
By the same token I do not turn off my 3458As as long as the line power is up.
There was a time I had a rack of 15 3458As running waiting to be sold.
We have a power outage about 1 time per year long enough to trip our julian 
date and time clock. We use it to track power up time.

I do not see anyone posting 3458A in stat mode data: mean, SDEV, High, and Low, 
Range, and Number of samples over extended time.
then reverse polarity and do it again.
Also DC cal values before and after Auto cal and Keysight cal would be nice to 
know.
Also using Before and after cal data from Keysight to correct values.
Do not adjust the Flukes  but keep a spreadsheet of best guess of its value.
Something like  mean of present guess + before cal data correction + after cal 
data correction.
Example:
Say you present guess (guess1) is 9.468 cal the meter using 9.468 and 
then read the cal var 1 (I think that is the one for the reference
board)
Your as found data should indicate how far off your reference is.  correct and 
call that guess2 After you get the meter back read cal var 1 and then use 
successive approximation to when caling to get the same value in var 1. That 
should be
guess3
So new guess is mean (guess1, guess2, guess3).
If you have better confidence in one guess or less confidence in an other the 
values could be weighted.
You never really know what the actual value is  a given time but do know it is 
changing.  You can guess at it's value like 9.468 is just a guess even if 
the real value is 9.4681 or even 9.468 with what we have you just 
cannot know for sure. There can alway be another digit.

Anyone want to poke some holes in what I wrote?
Does anyone have a better way to come up with a Cal value for a fluke 10 volt 
reference without sending it out for calibration?
Where could send it to get a better calibration and what would it cost?


On Thu, Mar 26, 2015 at 8:03 PM, J. L. Trantham jlt...@att.net wrote:

 A couple of years ago, I sat my 735C, a (at that time) recently 
 Agilent calibrated 3458A, and two 731B's on a bench and have left the 
 references on, with battery back-up for any power failure.  I have 
 turned the 3458A off and on a number of times in the interim.

 When I set all this up, I adjusted the 735C to 10.00 VDC as best I 
 could using the then recently calibrated 3458A and adjusted

Re: [volt-nuts] Fluke 731B

[J. L. Trantham]

A couple of years ago, I sat my 735C, a (at that time) recently Agilent 
calibrated 3458A, and two 731B's on a bench and have left the references on, 
with battery back-up for any power failure.  I have turned the 3458A off and on 
a number of times in the interim.

When I set all this up, I adjusted the 735C to 10.00 VDC as best I could 
using the then recently calibrated 3458A and adjusted the 731B's to match the 
735C using the 3458A as a 'null' meter.

Tonight, after the 3458A had been on for several weeks, I did the 'AutoCal All' 
on the 3458A and read each of the references.

The 735C measures about 10.16 VDC, and the 731B's measure about 10.05 
VDC each, within about 2 uV of each other.

In the next couple of months, I plan to send the 3458A back to Agilent/Keysight 
for recalibration and see what the meter measures 'as received' and 'as left'.

We'll see how close it is to being 'in tolerance' 'as received'.

Hope this helps.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Orin Eman
Sent: Monday, March 23, 2015 12:36 AM
To: Discussion of precise voltage measurement
Cc: richiem5...@gmail.com
Subject: Re: [volt-nuts] Fluke 731B

Richard,

Some really good information has already been posted.  Here is what I have 
found.

I posted a comparison of the 731B against the Geller Labs SVR-T here:

http://www.eevblog.com/forum/testgear/geller-labs-svr-and-svr-t/msg282582/#msg282582

There were within 1ppm of each other over 48 hours and 3.8 deg K.

I'm currently running a comparison against the reference from an HP 3458A, 
using an Agilent 34461A in _ratio_ mode.  A screen capture follows if the list 
lets it through.  There is only 5 hours here as I just updated the 34461A 
firmware (it adds another digit to the scaling limits on the trend chart and is 
definitely worthwhile).

One thing about the 731B is that it if the NiCd pack is dead or fully 
charged(!), there will be much more noise on the output.  I designed a 
'high-side' switch to switch between AC and battery power and it improves noise 
when the NiCd is fully charged.  (The original design is a diode switch and if 
you have a NiCd pack which has a high voltage when fully charged, the half-wave 
rectified AC that is used to charge the NiCd pack leaks through to the voltage 
reference power supply.)

A big WARNING.  If a 731B still has its NiCd pack installed, replace it.  I had 
Batteries Plus make me a replacement pack.  About $30 as I recall.  If the NiCd 
pack isn't installed, you need to remove the diode that goes from the battery 
pack to the voltage reference supply, or you'll get unfiltered half-wave 
rectified AC on your voltage reference power supply and it does get into the 
output!

My 731B seems to be doing quite well IMO, being within 1ppm of the new at the 
time Geller SVR-T.  It has also been reading 9.6 to 9.7 on the 34461A 
for the last year (as long as I don't turn on the 8568A that is next to the 
34461A... the 8568A blows warm air into the 34461A and then all bets are off).

Orin.

[image: Inline image 1]

On Sat, Mar 21, 2015 at 1:02 PM, Richard Moore richiem5...@gmail.com
wrote:

 Hi all — realisitcally, what sort of stability can be expected from a 
 fully functional 731B regarding variation in ambient temp a few 
 degrees C around 23, and for long-term drift?

 Fluke’s specs are very conservative, and I think the 731 is far better 
 than the specs would lead you to believe, but I have no practical 
 experience with these units.
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Re: [volt-nuts] plastic caps on 3458A reference board

[J. L. Trantham]

Frank,

Thanks for the info.  I've wondered about that.

In the days of 3D printers and CAD/CAM, it might be possible to have a 'run' of 
these 'made to order', so to speak.

I wonder if Linear Technology would have any information about them?

Thanks again.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Frank Stellmach
Sent: Wednesday, January 28, 2015 5:28 AM
To: volt-nuts@febo.com
Subject: [volt-nuts] plastic caps on 3458A reference board

Hello Joe,

yes the cap consists of two parts.
The upper one serves for thermal isolation of the LTZ1000A TO99 case against 
the environment and therefore reduces the power dissipation of the oven.

The part on the solder side is much more important, as it covers the solder 
joints and avoids air draught over these pins. That avoids these low frequency 
voltage variations, which are mentioned in the LTZ data sheet.

Anyhow, there are no further shieldings around the PCB, so the solder joints of 
the OP Amp and the precision resistors are exposed to that air draught, maybe 
from the fan.
That's a further engineering fault they made on this reference.

(The other faults are the 95°C oven temperature, the use of the A version 
instead of the non A, and the use of R417,200k temperature compensation 
resistor, which is necessary for the non A version only.)

The hat is not included in the BOM inside the CLIP, therefore can not be 
ordered from HP, obviously.

It is a smooth, shiny plastic, resembles the one used around the LM399H.
Wasn't latter one something like polysulphone?

Maybe suitable pieces of polystyrol foam will do the job also.

Frank
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Re: [volt-nuts] [Bulk] Re: 3458A reference boards on ebay

[J. L. Trantham]

When these boards are installed in a 3458A, the LTZ1000 is covered by a small, 
white, 'hat' that mounts with screws that pass through the two holes on 
opposite sides of the LTZ1000.  I've never removed the board to see if there is 
anything on the bottom of the board that would cover the bottom of the LTZ1000.

Does anyone know what this 'hat' is constructed of or the HP/Agilent/Keysight 
part number of this item is?  Is it available from Keysight?

In the 3458A the reference board is under a cover that covers about half of the 
top of the meter but not 'insulated' beyond that, except for the 'hat' referred 
to above.

It would appear desirable to find what that 'hat' is and see if something could 
be fabricated to 'insulate' the LTZ1000 for a 'do it yourself' standalone 
reference.

Would appreciate hearing anything about how the reference board is 'insulated' 
in the 3458A.

Thanks.

Joe


-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Orin Eman
Sent: Tuesday, January 27, 2015 11:45 AM
To: Discussion of precise voltage measurement
Subject: [Bulk] Re: [volt-nuts] 3458A reference boards on ebay

Dave,

I'll be putting it in an enclosure to use as a reference.  It will probably be 
a smallish diecast aluminium box.  It's what I did with my Geller SVR-T and it 
compared very well with my Fluke 731B.  I'll likely use Pomona 3770 binding 
posts for output (I used them to repair the 731B).  I'll also use the 
protection circuits from the Fluke 732 on the output - big reverse diode, gas 
discharge tube and TVS as I recall (I plan to add these protection circuits to 
the 731B).

I'll likely do a PCB for it, though the local equivalent of veroboard would 
likely be OK; the socket spacing is 0.9 and the pin spacing 0.1.  My meters 
are also 6 1/2 digit (3456A and 34461A) so I'm not too concerned with thermal 
EMFs with one count being 10uV on the 10V range.  However, I will try to avoid 
temperature gradients and keep the outputs close together.  I'll use star 
wiring for the 18V and ground as in the following:

http://www.maxmcarter.com/vref/

It is debatable whether the -15V supply is needed - I'll test with and without. 
 I'd add a few tantalum capacitors to the above design - on the regulator 
outputs and on the 3320 resistor, along with protection diodes for the LM317.

There is also a HUGE thread about the LTZ1000 on EEVBlog - I'll be reviewing 
that for ideas:

http://www.eevblog.com/forum/projects/ultra-precision-reference-ltz1000/

I actually have a couple of LTZ1000As here that I was going to DIY, but never 
got around to getting the precision resisters .  I think there is a source in 
England mentioned in the EEVBlog thread.

Orin.

On Tue, Jan 27, 2015 at 2:24 AM, Dr. David Kirkby (Kirkby Microwave Ltd)  
drkir...@kirkbymicrowave.co.uk wrote:

 On 27 January 2015 at 09:16, Orin Eman orin.e...@gmail.com wrote:
  There is a seller letting a slow trickle of them out there... they 
  seem
 to
  be going for about $165.  The current batch of two is around $100, 
  but
 will
  probably be bid up.
 
  I just received one that I won.  Seems to be working fine after a 
  quick breadboard lashup.  I'll be making an enclosure for it next.
 
  A little expensive IMO, but given the trouble getting the precision 
  resistors to DIY with the LTZ1000A, probably worth it.
 
  Orin

 Orin,

 What do you intend doing with it?

 I was thinking about getting one of those, with a view to putting it 
 in a box with a couple of terminals to have something to compare with 
 my 6.5 digit 3457A.  But what put me off is a lack of knowledge in 
 knowing how to convert a 3458A reference board into a boxed unit with 
 a known output voltage at the terminals. How would I avoid / control 
 thermal EMFs?

 I'd be interested to hear what your plans are for it, and how you 
 intend tackling those issues.

 Do you know what the difference in the reference is between a standard 
 3458A (8 ppm) and the high stability option 002 (4 ppm) model? I'm 
 guessing the chips for the option 002 might be the top performing 
 ones. I wonder if there's any way to tell from your board if it came 
 from a standard 3458A or a 3458A with option 002.

 Dave
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Re: [volt-nuts] HP3458A cal ram data dumper

[J. L. Trantham]

Mark,

I am very interested in this.  

I downloaded the file, saved it, double clicked the .EXE and got 'The program 
can't start because gpibib.dll is missing from your computer'.  What do I need 
to do with the .CPP file?  Do I need to install John Miles GPIBKIT library?

I already have MS Visual Studio 2010 Express installed.

Thanks for your help and please my 'EXTREME Newbie' status when it comes to 
working with 'code'.

I'm trying to install on a Win7Pro 64bit Core i7 laptop.

I have Prologix USB/GPIB, NI USB-GPIB-HS, and HP 82367B adapters that I can use.

Any pointers very much appreciated.

Thanks and Merry Christmas.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Mark Sims
Sent: Wednesday, December 24, 2014 5:25 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] HP3458A cal ram data dumper

I have uploaded a .ZIP file with the source code and Windows .EXE file for the 
calibration/data memory data dumper program here:
http://s000.tinyupload.com/index.php?file_id=0219779600667150

This output of this version of the program also produces a formatted/commented 
listing of what the various data values in the cal ram are.  
Program usage info is available by executing the program without any command 
line arguments.  Also see the comments at the start of the .CPP source code 
file.
Again,  this program is to be used in conjunction with John Miles GPIBKIT 
library.
Also many thanks to Poul-Henning Kamp for the hard work of documenting the 
HP3458 MREAD command and for figuring out everything about the cal ram memory 
map and contents.


  
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Re: [volt-nuts] HP3458A cal ram data dumper

[J. L. Trantham]

The .ZIP or the two individual files, .CPP and .EXE?

Thanks.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Mark Sims
Sent: Wednesday, December 24, 2014 6:41 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] HP3458A cal ram data dumper

Yes,  the program requires GPIBKIT.   Copy the code to the GPIBKIT directory.   
  
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Re: [volt-nuts] Old HP3458A - SN: 2823A 03939

[J. L. Trantham]

I suspect it has the six EPROM version of the A5 board, where the '5' firmware 
resides.  The Ver 8 files are 'out there' and it should be a simple matter of 
burning the six chips if you have a chip burner.  

I don't know where the '1' firmware resides.

Joe

-Original Message-
From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of cfo
Sent: Tuesday, September 23, 2014 1:57 PM
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Old HP3458A - SN: 2823A 03939

On Sun, 21 Sep 2014 15:22:14 +, cfo wrote:

 Gents
 
 I'm looking for a 3458A , and have found one : SN: 2823A 03939 w. opt
 002 Seller says it's passing selftest.

The seller has returned with this info : 

 hello again too,
 rev : 5,1
 i think CAL-Ram's have been changed on 1999 but i m not sure.
 In can accept a 30 days warranty no problem.

So it's fw: 5,1

CFO

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Re: [volt-nuts] 732A drift

[J. L. Trantham]

I think the 'IN CAL' LED has to do with a 'minimum voltage' but I don't
think it has to with a minimum battery voltage.

When you remove the battery pack, with the unit plugged in, I don't think
the 'IN CAL' LED goes out.  Otherwise, you would never be able to swap
battery packs.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 6:21 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift

The output impedance of both the 1v outputs is ~1k ohm. I wonder if Randy
could check the 3458a input impedance with a 10M ohm resistor and the 10v
output of the 732a. 

I was thinking that the 732a needed a minimum battery voltage to allow the
in cal led to turn on with the short to the Lo terminal. I guess I could try
it on one of mine that is waiting for repair.


Todd

Sent from my iPad

 On Aug 23, 2014, at 6:42, J. L. Trantham jlt...@att.net wrote:
 
 Randy,
 
 The 'IN CAL' LED is turned on as Todd describes.  It goes off if power 
 to the unit is lost and, thus, calibration is lost.  It is not related 
 to the battery charge LED.
 
 As I understand it, the units are designed to powered on 24/7/365 and 
 are 'IN CAL' once they are powered up, stable (weeks, months?), and 
 have been calibrated by your reference lab.  Once power is lost, 
 meaning lost AC and batteries depleted, the 'IN CAL' light goes out 
 and outputs are thereafter unreliable.
 
 Once you decide to get the 732A calibrated, you will need to find a 
 way to ship it to the reference lab and get it shipped back while 
 continuously powered, connecting an external battery pack to the 
 connector on the back of the battery pack.  The internal battery pack 
 is likely to last only a few hours.
 
 There are at least two types of connectors for an external battery, 
 two 5 way binding posts and a Hypertronics connector which is a small 
 black connector about 'dime' sized.  I can find the part number for 
 the mating connector if you need it.
 
 I think the +/- 1 uV drift with the 10 V output and the 3458A are 
 within specs for both the 732A and 3458A.
 
 Not sure what to think about the drift on the other readings unless 
 there is some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or
ground.
 
 Good luck.
 
 Joe
 
 
 
 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of Todd Micallef
 Sent: Saturday, August 23, 2014 4:13 AM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] 732A drift
 
 Randy,
 
 I looked at the 3458a input impedance, and it is difficult to get the 
 meter set to the FixedZ (10M) mode. However, the 100v range is 10M. It 
 should default to HiZ on reset.
 
 I forgot to mention to check the outputs and guard resistance to 
 ground. One of my 732a had some foam baffling under the cover that had 
 dry rotted. There was a lot of leakage to ground.
 I can't remember if the foam was on the older or newer versions of the
732a.
 
 The cal light comes on with a short wire stuck in the hole and 
 connected to a LO output terminal. I don't know, but maybe the battery 
 charge led has to be off.
 
 Todd
 
 Sent from my iPad
 
 On Aug 23, 2014, at 1:16, Randy Evans randyevans2...@gmail.com wrote:
 
 I hope someone can help with a strange anomaly on either my 3458A or 
 the 732A.  The 732A 10V output as measured on my 3458A seems 
 relatively stable over time (it bounces around about +/-1 uV but is 
 it the
 732 or the 3458?).
 However, the 1.000 VDC output drifts downward at a rate around 1-2 uV 
 per second as soon as I plug the 3458A into the 732 output. If I 
 remove the 3458A and connect it back up after a few 10s of seconds, 
 the reading goes back to what it started at and then drifts downward 
 again.  The 1.018V output also drifts downward but at a much slower 
 rate and not as much.  Now the question is: is it the 732 or the 
 3458A?  I tried to see it on my Agilent 34401A DMM but it really 
 doesn't have the resolution, but I do seem to see it on the 1.000VDC 
 output.  If it is the 732A, what would cause it to drift downward 
 like that?  Since the 3458A has an input impedance of
 10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even 
 see
 the difference of whether the 3458A is connected of not, but it 
 clearly makes a difference as to how long its connected and how long 
 it's been disconnected.
 
 Any one have any conjectures?
 
 Also, what will turn on the In Cal light?  What does it mean if it 
 doesn't come on?
 
 Thanks,
 
 Randy
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Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memory chips?

[J. L. Trantham]

Mark,

Would love to try it.

I think the main reason to hang onto the calibration data is to be able to
send the meter to Keysight and find out if the meter was 'in spec' when it
arrived for calibration.  If so, gives great confidence that the meter is a
'good one'.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Mark Sims
Sent: Thursday, August 21, 2014 1:53 AM
To: volt-nuts@febo.com
Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memory
chips?

I'm porting over my HP3458A NVRAM data dumper program to use John Miles
GPIBKIT routines.  It should make it usable with most GPIB interfaces out
there and be able to run under more modern versions of Windoze.   
My first crack at it is working,  but it is quite a bit slower than my
original program.  Not sure if anything can be done about that...  BTW, my
program does verify the checksum bytes in the CAL ram so there is a check
that the dump went OK.  Without Poul-Henning's work none of this would be
possible. 
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Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips?

[J. L. Trantham]

Bill,

Thanks for the insight.  

I always thought that I lost my CALRAM data by trying to read the chip in my
programmer while the chip was still warm.  What you are saying is that you
did not try to read your chip, just unsoldered, installed a socket, plugged
it back in and the data was corrupted.

Very interesting.

I have done this to three 3458A's and only lost the data on one of the
units.

This further supports the need to be able to read the contents before
unsoldering and have that data be able to be used to program a new chip.

Thanks for the insight and I would love to try some programs to do that.  I
only have Windows systems but I have several USB to GPIB adapter choices,
PCI to HPIB adapter choices, and RS232 to GPIB adapter choices.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Bill Gold
Sent: Thursday, August 21, 2014 9:33 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K
memorychips?

When I removed the original NVRAM devices and then put in sockets, I plugged
the original devices back in just to see if everything worked.  Apparently
some cal data was lost just desoldering the devices as I got error messages.
It really didn't concern me as I intended to completely recal the meter with
my local standards anyhow.  It was hours before I plugged the original
devices back in so they were completely at room temp.  My guess was that
since the date codes were 1992 and I did this in 2010 the batteries were
almost dead after 18 years and just the shock of desoldering caused the
end.

Bill
- Original Message -
From: Mark Sims hol...@hotmail.com
To: volt-nuts@febo.com
Sent: Wednesday, August 20, 2014 7:20 PM
Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K
memorychips?


 The problem with removing the chip and copying it is the very real chance
of glitching the contents in the process.  Much better to make a backup copy
first.

 The 32Kx8 NVRAMS are used for system memory and things like storage of
user programs and data.

 Note that the two 32Kx8 devices are form a 16-bit word.  The 2kx8 cal ram
is only on the high byte of the data bus.  MREAD returns memory contents as
a signed integer value (-32768..32767) in ASCII.
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Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memory chips?

[J. L. Trantham]

John,

I don't think I would worry too much about messing up the 'CALRAM'.  If you
'mess up' the 'CALRAM', and your meter is, otherwise, OK, you will spend
about $500 with Keysight for a 'Keysight' calibration, which I would
recommend.

If they get your meter and it is not 'suitable' for calibration (meaning
that, in some way, it's 'broken'), you will be notified and offered the
option of having them 'repair' the meter (for about $2700, which includes
the 'Keysight' calibration) or returning the meter to you for your repair at
a cost of half the calibration charge, IIRC.

The key point about reading these NVRAM's is to, first and foremost, let the
chips cool after removal before trying to read them.  I learned about that
the hard way.

Second, make sure your programmer specifically supports the chip you are
trying to read and program.  If so, reading then archiving the data should
be straight forward and programming a new chip should be equally straight
forward.

I am not familiar with the 'Mem test 1 high' issue but I suspect the
Assembly Level Repair Manual or the Component Level Repair Manual should
address the issue.  I agree with others that this likely means that, in some
way, your meter is 'broken'.  If you can chase that down to a simple problem
and repair it, getting the calibration with Keysight would be the next order
of business.  Once it passes calibration, you would be able to purchase the
'Repair Agreement' for a couple hundred dollars per year, with a discount
for multiple year purchases up to a maximum of 5, IIRC, which gives you a
meter with a 'factory warranty' for that time period.

Personally, I would look for a 'professional' programmer rather than one of
the 'cheaper' ones, especially if you are anticipating getting into vintage
equipment and programming EPROM's, etc.  BP Micro, Advin, DATA I/O, Elnec,
etc., would ones I would look for.  I'm sure others on the list would have
their own recommendations.  The prices on theBay right now are particularly
ridiculous but good deals can be had.  The majority of these units use
parallel port connections and need WinXP as the OS.  The later versions,
starting around $500 will connect via USB and be able to utilize Win7 or
Win8.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, August 20, 2014 8:41 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K
memory chips?

I do have a ni gpib-usb-hs
http://sine.ni.com/nips/cds/view/p/lang/en/nid/201586
I was hoping to remove the chip, read the data with a usb programer and
wright the data back into a new chip before installing it.
Then do a full calibration.
If the 16k chip has the cal vars what do the other 32k chips have?
Thanks for the input.
I should be able to read to read the data from a good meter with the MREAD
and wright it with a programer.

I have been using excl to read program 3458As  I will see if I can get MREAD
to work there.




On Wed, Aug 20, 2014 at 5:33 PM, Mark Sims hol...@hotmail.com wrote:

 You REALLY don't want to mess with that 24 pin NVRAM chip... it 
 contains the calibration memory.  If you bugger the data in it,  you 
 get to spend a couple of grand getting the meter back into working 
 order.  I know a couple of people that did just that.

 The solution is to first make a backup copy of the memory contents 
 using the (undocumented) MREAD command over the GPIB bus.  
 Poul-Henning Kamp figured out how to do it... buy the man a beer... even
better a case of
 beer...   Search the archives for details.

 I just backed up all the memory in my 3 HP3458A's for when the inevitable
 BIG BAD DAY comes and the backup batteries go bye-bye.   If you happen to
 have a NI GPIB-232CV-A (or possibly a Prologix) RS-232 to GPIB 
 converter and can run a DOS or WIN98 program,  I have a program that 
 dumps the memory chips.  It has code for the Prologix in it,  but I've 
 only used it with my a Prologix compatible unit I built... I don't 
 have a real Prologix to test it with.


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-- 

*John Phillips*
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Re: [volt-nuts] New HP3458A

[J. L. Trantham]

Randy,

Congratulations on your 'new' 3458A.

The 'CALRAM' back-up was just recently covered.  There are two options:  

1.  Remove the NVRAM, read its contents with a programmer, program a new
NVRAM and install the new NVRAM.  I chose that option, installing sockets
for the 'CALRAM' and the two other NVRAM's that are used for other,
non-calibration, purposes.  Be sure to let the NVRAM cool all the way down
before trying to read it.  Learned by experience with that one.

2.  Read the 'CALRAM' via HPIB and the MREAD command (many steps involved
but can be done as a program with your laptop/desktop), use that data to
program a new NVRAM (I suspect there is a way to 'program' the NVRAM by HPIB
as well but I don't recall ever reading anything about it on the list),
remove the old NVRAM and install the new NVRAM.

When I read the contents of the 'CALRAM' with a programmer and with the
MREAD command, they matched exactly.  However, when you do an ACAL, the
CALRAM contents change.

Does your unit have the single EPROM or the 6 EPROM version of the firmware?
Also what version of firmware do you have?  The latest is REV 9.  REV 8 is
'out there' on the net.  If you purchase an exchange display, and you have
the single EPROM version of the A5 Outguard Controller Assembly, the REV 9
EPROM is $24.10 per the Keysight website.  Might be worth adding to the
order.   The 6 EPROM version is $220.

Also, what is the serial number?  You can get a good idea of age by the
serial number.  Also, the various covers inside often will have dates of
manufacture on them and the chips, etc., will have date codes, including the
NVRAM's.

Also, you can add option 001 by plugging some memory chips, specific details
I don't recall right now.

As far as the reading when shorted, I recall the Calibration Manual calls
for a piece of copper wire to short the input terminals.  It looks like a
flying 'U' when properly fashioned.  The Calibration Manual gives the
details, IIRC.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Randy Evans
Sent: Friday, August 15, 2014 8:40 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] New HP3458A

I would like to thank everyone that replied to my query on what to look for
in my new HP-3458.  I did find that the AUTO ZERO button does work fine,
thanks to Bill's comments.  I had looked in the manual, just not far enough.

The display is still perfectly readable but i would like it to be perfect.
I am particularly interested in the exchange display for $272 (better than
$700 for a new one, as Todd suggested).  Does someone have a contact number
at Keysight that I could call (my experience is that one can spend a lot of
time calling around until the right person is finally found).

I certainly need to figure out how to copy and replace  the NVRAM - I lost
the calibration on my Datron 1082 by not realizing the memory backup battery
died and now I need to calibrate it myself (the HP3458A should make that
doable, I hope).  Any suggestions would be greatly appreciated.  I believe
it has been covered before on Volt-Nuts and I need to go through the past
discussions to find it.

One question I have for the group is what should the display typically show
with the input shorted?  I see a reading of about -.0025 mV.  That seems
rather high.  I tried several different banana cables (gold plated, tin
plated) used to short the input terminals  to see if thermocouple effects
might be responsible but there was no change in the reading.

Still learning.

Thanks,

Randy



On Fri, Aug 15, 2014 at 8:06 AM, Jason Watson watson.ja...@gmail.com
wrote:

 I've also seen excessive Guard to Low leakage when varistor RV501 has 
 gone bad (it's located on the front/rear switch pcb and it's possible 
 to replace it while leaving the circuit board in place if you are
careful).
  HP/Agilent/Keysight Part number is 0837-0196, cross referenced to a 
 Harris Corp. V430MA3A.


 On Fri, Aug 15, 2014 at 10:46 AM, Stephen Grady 
 grady.st...@gmail.com
 wrote:

  Randy,
 
  I have come across a few 3458A's that had leakage between Guard and 
  Low when te guard is in external guard position. This was due to a 
  leaky external guard switch and/or leaky front rear switch. This can 
  be quickly
 determined
  by measuring resistance between guard and low with guard external. 
  This normally in not an issue except when you are using 3458A to 
  measure
 voltage
  with low above earth potential say in a bridge the guard low leakage 
  will be loading other arm of the bridge.
 
  Kind Regards,
 
  Steve Grady
  Sydney, Australia
 
  -Original Message-
  From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
  On Behalf Of Randy Evans
  Sent: Friday, 15 August 2014 1:22 PM
  To: volt-nuts@febo.com
  Subject: [volt-nuts] New HP3458A
 
  I picked up a used HP3458A today, which I needed for some precision 
  DC measurements i need to 

Re: [volt-nuts] HP3458A calibration memory backup

[J. L. Trantham]

Poul,

I would love to know where the CALNUM value is stored.

Any idea?

Thanks.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Thursday, August 07, 2014 12:36 AM
To: Discussion of precise voltage measurement; Mark Sims
Subject: Re: [volt-nuts] HP3458A calibration memory backup


In message blu170-w4732a073be87463ff74529ce...@phx.gbl, Mark Sims writes:
I have three HP3458A's and decided it was time to back up the battery 
backed static RAM chips.  [...]

I dumped the third
machine from a cold start and one byte was different between each dump.

If you mail those files to me, I can try to see if that bit matters.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [volt-nuts] Buying HP-3458A

[J. L. Trantham]

Randy,

Yes, that is my understanding.  The person who would be able to definitively 
answer this question is Gary Bierman at Agilent at the Loveland Calibration 
Lab.  A very knowledgeable person regarding the 3458A.  I had a long talk with 
him before undertaking the purchase of my 3458A's.  I wound up with three 
3458A's for about the price of one new one.  All three 3458A's turned out to be 
functional with no failures.  All three were of similar 1990's to early 2000's 
vintage with the same major components.  Two were HP and one was Agilent, all 
made in the US.  I had no Malaysian units.

I removed the three Dallas chips in each of them, installed sockets, and 
installed new Dallas chips that I programmed with the data from their 
respective removed chips.  A total of 9 Dallas chips for the three units.

I also removed the single EPROM in each of them, installed a socket, and 
updated the firmware to the latest version I could find.

I managed to lose the CAL data from one of the units by, I think, trying to 
read it while still warm from the unsoldering process.  I calibrated that unit 
using some 'home standards' and a recently calibrated Solartron 7081 as the 
'transfer standard'.

I then sent the units in for Agilent Calibration, all three of which passed.  
Then I was able to avail myself of their 'service agreement' for each of the 
units.

They all agree very closely when measuring my now somewhat upgraded 'home 
standards'.

They are truly impressive units.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf 
Of Randy Evans
Sent: Tuesday, July 08, 2014 9:29 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Buying HP-3458A

Joe,

I imply from your e-mail that if I get a cheap 3458A that is complete but 
doesn't work, Agilent will repair it and calibrate it for a fixed fee of 
$2740.46, regardless of what is wrong with it?

Of course that means i would need to insure the unit is complete with no 
missing parts.

Randy


On Sun, Jul 6, 2014 at 3:15 PM, J. L. Trantham jlt...@att.net wrote:

 It is worth mentioning (re-mentioning) that once your 3458A passes 
 calibration with HP/Agilent/Keysight, etc., it becomes eligible for 
 their 'repair agreement' at $178.68 per year (with a small discount if 
 you purchase multiple years, up to a maximum of five years).  This 
 means that if it 'breaks' within that time period, it is repaired and 
 recalibrated for no additional charge.

 Per the Agilent US site, the 'repair per incident' charge is $2740.46.

 So, if you happen to get a 'good' 3458A that Agilent calibrates, you 
 can then get the service agreement (insurance policy?), which applies 
 even if you do not change the NVRAM's.  If they die, send it back to 
 Agilent and they will repair and recalibrate.

 In my shop, the 3458A is the 'house standard' that I use to measure 
 the resistance standards and voltage standards that I have.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of R.Phillips
 Sent: Sunday, July 06, 2014 2:08 PM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] Buying HP-3458A

 Randy
 I'm already forgetting some of the facts that made up the price that I 
 paid for the repair and re-cal. for my 3458A, as I have been involved 
 in a number of other restoration/repairs, but it was remarkably 
 similar in £ sterling, against your US $ price - so I guess it would 
 seem to be a fixed charge ? My instrument failed when the 'classic' 
 RAM/ROM 's ran out of battery support and further, they found another section 
 which had gone bad.
 There's nothing to give your more confidence than the Agilent 
 Calibration Certificate that comes with the package,as this is 
 probably the prime instrument in the collection of we lucky owners, so 
 it has to be good.  As I have stated in a previous exchange, the 'new' 
 processor/ROM/RAM board is now fitted with sockets, and the devices 
 that were formerly fitted, have been replaced with the new type that 
 only connect the battery support power when they are plugged in to their 
 sockets.
 Roy


 -Original Message-
 From: Randy Evans
 Sent: Sunday, July 06, 2014 6:44 PM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] Buying HP-3458A

 That e-mail I referenced is several years old.  i believe the current 
 repair price is just over $2800.

 Randy


 On Sat, Jul 5, 2014 at 10:49 PM, John Phillips 
 john.philli...@gmail.com
 wrote:

  ​They do really offer that service as​ long as you send them a 
  complete meter... No missing parts. Well they will take a few 
  missing screws and such. My experience with them is they charge the 
  same no mater what need to be fixed. Not sure what the price is, 
  there prices are country dependent.
  I
  thought it was a little more than $2200 last I checked.
 
 
  On Sat, Jul 5, 2014 at 4:08 PM

Re: [volt-nuts] AC Voltage Measurement Standards

[J. L. Trantham]

John,

Thanks for the reply.  I have both of those.  

What I'm thinking about is a measurement standard.  That is, how do I know
that my 'standards' are accurate?

That brings to mind the 'thermal converter' issue.  The 8506A apparently
uses a 'thermal converter' as part of its measurement process.  The
individual A55 Thermal Converters can be used for their various ranges but
might be more expensive if you collect all of them.

So, the question is how would you go about 'proving' that your reference is
indeed accurate?  As best I can tell, this has to do with comparing it to
some DC reference by virtue of an RMS (thermal, as best I can tell)
comparison.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Tuesday, July 08, 2014 8:57 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] AC Voltage Measurement Standards

I like the 5200A for a good stable unit up to 110 volts but if you go above
that you would be better off with a 5100B which will do 1100 volts.


On Tue, Jul 8, 2014 at 6:46 PM, J. L. Trantham jlt...@att.net wrote:

 I've been thinking about adding an AC Voltage Measurement Standard to 
 my shop.



 It would appear that most of these have to do with thermal converters.
  Does
 anyone have any thoughts about this?



 I've been thinking about a Fluke 540B, 8506A, or a collection of A55 
 Thermal Converters.  I have accurate DC measurement tools and DC 
 standards.



 I would appreciate any thoughts.



 Thanks in advance.



 Joe

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-- 
John Phillips
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Re: [volt-nuts] Buying HP-3458A

[J. L. Trantham]

It is worth mentioning (re-mentioning) that once your 3458A passes calibration 
with HP/Agilent/Keysight, etc., it becomes eligible for their 'repair 
agreement' at $178.68 per year (with a small discount if you purchase multiple 
years, up to a maximum of five years).  This means that if it 'breaks' within 
that time period, it is repaired and recalibrated for no additional charge.

Per the Agilent US site, the 'repair per incident' charge is $2740.46.  

So, if you happen to get a 'good' 3458A that Agilent calibrates, you can then 
get the service agreement (insurance policy?), which applies even if you do not 
change the NVRAM's.  If they die, send it back to Agilent and they will repair 
and recalibrate.

In my shop, the 3458A is the 'house standard' that I use to measure the 
resistance standards and voltage standards that I have.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf 
Of R.Phillips
Sent: Sunday, July 06, 2014 2:08 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Buying HP-3458A

Randy
I'm already forgetting some of the facts that made up the price that I paid for 
the repair and re-cal. for my 3458A, as I have been involved in a number of 
other restoration/repairs, but it was remarkably similar in £ sterling, against 
your US $ price - so I guess it would seem to be a fixed charge ? My instrument 
failed when the 'classic' RAM/ROM 's ran out of battery support and further, 
they found another section which had gone bad. There's nothing to give your 
more confidence than the Agilent Calibration Certificate that comes with the 
package,as this is probably the prime instrument in the collection of we lucky 
owners, so it has to be good.  As I have stated in a previous exchange, the 
'new' processor/ROM/RAM board is now fitted with sockets, and the devices that 
were formerly fitted, have been replaced with the new type that only connect 
the battery support power when they are plugged in to their sockets.
Roy


-Original Message-
From: Randy Evans
Sent: Sunday, July 06, 2014 6:44 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Buying HP-3458A

That e-mail I referenced is several years old.  i believe the current repair 
price is just over $2800.

Randy


On Sat, Jul 5, 2014 at 10:49 PM, John Phillips john.philli...@gmail.com
wrote:

 ​They do really offer that service as​ long as you send them a 
 complete meter... No missing parts. Well they will take a few missing 
 screws and such. My experience with them is they charge the same no 
 mater what need to be fixed. Not sure what the price is, there prices 
 are country dependent.
 I
 thought it was a little more than $2200 last I checked.


 On Sat, Jul 5, 2014 at 4:08 PM, Randy Evans randyevans2...@gmail.com
 wrote:

  I am in the market for a used HP-3458A and, in researching past
 messages, I
  came across an interesting question:
 
  *Chris Erickson* ericksonc2 at comcast.net volt-nuts%
 
 40febo.com?Subject=Re%3A%20%5Bvolt-nuts%5D%203458A%20questionsIn-Repl
 y-To=%3C001b01cc7960%24a15d2840%24e41778c0%24%40net%3E
  
  *Thu Sep 22 19:48:41 UTC 2011*
 
  If Agilent will fix everything, bring it up to specs, and calibrate 
  it no
 
  matter what's wrong with it for $2200, then why would I spend 
  $5000-6000
 or
 
  more for one that is in good shape - even if calibrated? Just grab 
  the first
 
  bargain that comes along for $1500-3000, send it straight to Agilent 
  and
 be
 
  money ahead. Seems the better course of action to me if that price 
  is
 
  accurate - do they really offer this service?
 
 
 
 
  I could not find an answer to this question but it does beg the 
  question.
   Does nayone have an answer as to why not buy the cheapest unit and 
  send
 it
  in for repair?
 
 
  Thanks,
 
 
  Randy Evans
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  and follow the instructions there.
 



 --
 John Phillips
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Re: [volt-nuts] A Fluke 732A: Return it or keep it? - 3458A

[J. L. Trantham]

Roy,

The 3458A is quite the instrument.  I'm not familiar with the latest
'plug-in/power-up' devices of which you speak.  I suspect you have Rev 9.2.
Mine have the single chip EPROM, through-hole, A5 board.  I suspect yours
has the SMT version.

If you have just had Agilent calibrate the meter, it is now eligible for the
Repair Agreement for $178.68 per year.  You can buy up to 5 year's worth and
get a slight discount, 4% or so, IIRC.

Might be worth considering.

Gary Bierman at Agilent Loveland told me about that.  When I called Agilent
to purchase that, they were a bit skeptical.  However, when I told them that
Gary Bierman told me it was possible, they got on the phone to talk to
someone and then readily sold me the agreement.  Not a bad price to cover a
potentially expensive repair, especially if you plan to leave it on 24/7/365
and you don't know it's history.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of R.Phillips
Sent: Saturday, June 14, 2014 4:00 AM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?

Joe, Bill and Charlie
Thank you all for your advice, and for the short term I will leave the 732A
as is. Like you Joe, my 732A arrived with a set of 'dead' SLA batteries -
these were replaced, and its been powered 24/7 since last October, again it
came with no history. I bought mine from a dealer on the West Coast who had
a batch of 14, so I guess that they came from a lab.  Its stability is
impressive, and the Thermistor reading is currently 4.5194 K ohms, with only
small variations over time.
My 3458A had a new processor/RAM/ROM board fitted by Agilent - so it has the
latest 'plug-in/power-up' devices which I understand are a great
improvement, and was calibrated just about six weeks ago. I take your point
that the 3458A should be power continuously, but of course the display is of
the fluorescent type which deteriorate over time. This is now less
important, as I have had a new display installed, and the improvement is
great. I certainly agree that the 3458A is very sensitive to temperature
changes and as you advise, I frequently run 'Auto Cal' .  I consider the
cost of its refurbishment/calibration to be well worth while, considering
the cost of a new instrument.
Best regards.
Roy


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Re: [volt-nuts] A Fluke 732A: Return it or keep it?

[J. L. Trantham]

 another small change 
 you won't have to go through the same problem of trying again and again to
engage.
  I have found that turning the pots may cause a drift which will 
 show up days later due to the pot being dirty or whatever.  So what 
 I usually do is to turn the pot back and forth over several 
 revolutions so that I can clean the contact wiper.  I usually make 
 an initial adjustment and then turn the pot about 1/32 of a turn in 
 the opposite direction just to relieve any stress that might be 
 there and cause a small change in the output voltage.  I usually have very
good results with these methods.
  But I will agree with Joe that sometimes it is better just to 
 leave things alone and just use the known offset from 10 volts when 
 checking or doing cals.
 Bill


 - Original Message -
 From: Todd Micallef tmical...@gmail.com
 To: Discussion of precise voltage measurement volt-nuts@febo.com
 Sent: Thursday, June 12, 2014 7:20 AM
 Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?


 Roy,

 The 732A uses the 3059Y-1-101 type cermet pot for the 10V adjustment. 
 You can use a simple plastic tweaking tool for adjustment. I believe 
 you will need a fairly long tool. You can shine a light into one of 
 the other holes to see the orientation of the pot. However, many 
 people may prefer to
 leave
 the pot as is and just record the readings. It is going to drift 
 anyway
 and
 won't stay adjusted for long. The drift may worsen once the pot 
 position has changed too. I have adjusted mine, but only after the 
 broken pots were replaced.

 Todd


 On Thu, Jun 12, 2014 at 9:57 AM, R.Phillips phill...@btinternet.com
 wrote:
 Hi Joe
 Sorry if I am retracing steps, but I have recently had my 3458A 
 restored/recal'd  by Agilent - its good to have it back. I also have 
 a Fluke 732A which I can now check. Currently it is 10.24 volts, 
 I now feel confident to trim it to the 3458A. I have tried to see 
 the trimmers
 in
 each of the three holes - they appear to be some way within, and I 
 am wondering if you could confirm the type of pot. that is used and 
 just
 how
 long a trimming device is required. Is this a special tool only
 available
 from Fluke ?
 Regards
 Roy Phillips.


 -Original Message- From: J. L. Trantham
 Sent: Saturday, March 08, 2014 10:09 PM

 To: 'Discussion of precise voltage measurement'
 Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?

 Charles,

 What size batteries did you use for your external pack and where are 
 you located?  In other words, how long can your external battery 
 pack
 'survive'
 keeping the 732A 'hot'?  Is the external pack recharged at Fluke or 
 does
 it
 have to make a round trip on the initial charge?  Once I am 
 convinced my unit is stable (which will probably be another six 
 months or so, after I get my 3458A's re-calibrated by Agilent), I 
 hope to be able to send it to
 Fluke
 for calibration.

 Fluke made a transit case (732A-7002) and a Battery Charger and
 Auxiliary
 Battery Case (732A-7003).  However, I have never seen a picture of
 either
 of
 these.  Does anyone have any information on these?

 How did you make your case?  Did you include a charger?  Combination 
 of battery pack and shipping container or separate battery pack and
 shipping
 container?

 I was thinking of building a case with built-in charger, fuse, and 
 AC connector and cord such that when the unit arrived at the CAL 
 facility
 all
 that would be needed would be to plug it in and allow the external
 battery
 pack to recharge while the unit being calibrated was plugged in,
 recharge
 the internal batteries, and calibrated.  Or does the 732A also 
 charge
 the
 external battery pack along with the internal batteries?

 The connector you need (complete with female contacts) is a 
 Hypertronics P/N D01PB306FSTAH and is in stock at Kensington 
 Electronics at $8.96 each
 (plus
 tax and shipping).  Only problem is their $50 minimum order.

 The 'shell' only is P/N D01PB306NT and the female contact is P/N 
 YSK006-010ANH (three needed).

 http://ecommerce.keiconn.com/hypertronics/D01PB306FSTAH

 I ordered two of the connectors from Fluke using a P/N that one of 
 the Fluke folks in their eCal facility gave me, noting that someone 
 else had asked the same question a couple of weeks earlier, with 
 Fluke Item# 2181497, described as '100-166, PLUG - MALE, 
 HYPERTRONICS'.  They were $12.31 each (plus
 tax
 and shipping) and arrived as the shell only, no contacts.

 If Fluke solves their supply chain problem, I sure would like to get 
 the six female contacts I need to make my connectors 'complete'.  
 When I got on
 the
 phone with Fluke, I could never find anyone that had any knowledge 
 about this.  Is there anyone there I should ask for that might 
 understand my question?

 I look forward to your posting the update from Fluke.

 Thanks.

 Joe


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Re: [volt-nuts] 3458a with 202: Slave Test Convergence (sigh)

[J. L. Trantham]

Willy,

I would encourage you to call Gary Bierman at Agilent/Keysight, Loveland,
CO, and ask him your questions.

He is very easy to talk to and open to any question or thought about how to
proceed.  IMO, he takes a personal interest in these instruments and wants
to make them the best that HP/Agilent/Keysight can produce.

From my conversations with him, they prefer to do component level repair,
not assembly level repair, and take advantage of all the 'aging' that has
occurred over the years.  Obviously, if there is something that is
destroyed, they will do an assembly replacement, not component level repair.

If you opt for their 'Repair Per Incident', at $2740.46, they will bring it
up to 'spec', provide the 'Agilent Cal' and return it to you, eligible for
their Repair Agreement at $178.68 per year, with a discount available for
muti-year agreements, up to 5 when I did that.  I don't know if that would
include compliance with all Service Notes or not but I'm sure Gary can
answer that question.  They do not routinely replace the Dallas chips but,
if they have failed, they will be replaced.  If you get the Repair Agreement
and the Dallas chips subsequently fail, they will replace them and provide a
fresh Agilent Cal, at no charge (except probably for shipping) except for
the annual rate of $178.68 that you would have already paid.  It is easy to
remove the Dallas chips and install sockets.  You can read the chips,
archive the data, then program a new chip and install it.  Just don't try to
read the chip when it is still warm from the removal process.  Trust me on
this. :^).

I don't know about the firmware upgrade but, again, Gary Bierman can answer
that question.  One thing I was wondering about recently is whether it is
possible to upgrade the 'inguard' firmware to version 2 or if it has to be
done at Agilent.  The 'outguard' firmware is upgradeable by removing and
replacing the EPROM (or six EPROM's, depending on which version of A5 you
have) with a new one (or set) from Agilent.

The only thing you need to achieve in order to qualify for eligibility for
the Repair Agreement is to send the meter in and have it able to be Cal'd.
If it passes their calibration process, then it is 'up to spec' and is
eligible for their Repair Agreement, as I understand it.

However, I defer to Gary Bierman regarding all of this.  You can't go wrong
calling him and seeing what he has to say.

My guess is that he will be able to make a recommendation to you about how
to proceed and be able to give you some insight into what the problem is and
how to resolve it.  Depending on what the issues are, it might be
easier/cheaper to fix it yourself or return it to Agilent.

Others on the list have great experience with these DMM's and I'm sure will
provide their insight as well.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of new
Sent: Thursday, March 27, 2014 1:36 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] 3458a with 202: Slave Test Convergence (sigh)

I know that HP will (gladly?) take your sick 3458 and bring it up to current
specs, followed by a calibration. Since my sick one is at engineering level
2 or 3.something, it must be like it was built in 1989 - the dates on some
components.

Should I try to do any troubleshooting, or just send it to HP?  

Will they upgrade the current (aged and pretty much not drifting) boards?

Or do they take a good board from their stock and replace the current board
with one that may be new and 'drifty'?

I have read here that there are some unlisted upgrades that they do, also.

The RAM batteries will be replaced also, right? 

The biggest positive I see is the ability to go on the service plan and
never have to worry about a failure again after the 3458 is brought up to
current standards.

Willy
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Re: [volt-nuts] A Fluke 732A: Return it or keep it?

[J. L. Trantham]

Charles,

Thanks for the info on batteries.  I agree, some are definitely better than
others.  However, I'm no 'connoisseur' of batteries yet.  The 732A I got was
'unknown working condition' and I wanted the cheapest batteries I could find
to test the unit and see if I could get it up and running.  So far, it looks
good.

Do you wind up having to re-solder some of the battery wires in the battery
module in order to use the 12 V 5 AH batteries or will they just swing to
the other side since it appears that the (+) and (-) terminals will wind up
on the same side, instead of opposite sides with the 6 V 4.5 AH batteries?

I have not faced the shipping question yet, but, as David pointed out, there
is an issue with shipping batteries.  I suspect it could be shipped but
would be ground and, therefore, need a huge battery in order to get it to
the other side of the country 'hot'.  I recall reading some thoughts on
current drain for the unit when on batteries but I do not remember what it
was.  Clearly, it should be at a minimum, and therefore the battery should
last the longest, when already 'hot' when removed from AC power.  Has anyone
done that experiment?  I live in NW FL and I am not aware of Cal Labs in my
neighborhood that could do the work.  Atlanta, perhaps?  Does anyone have a
recommendation of a capable Cal facility 'close by' to NW FL?

Short of sending it to Fluke or another facility, I will be limited to using
my Agilent Cal'd 3458A to 'adjust' the 732A, then 'tracking' the 732A from
year to year as the 3458A comes back from Cal.

I paid less than Michael and more than you for my unit but it seems to work.
I have seen these sell on theBay for $450 and up.

Joe


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Re: [volt-nuts] A Fluke 732A: Return it or keep it?

[J. L. Trantham]

Charles,

What size batteries did you use for your external pack and where are you
located?  In other words, how long can your external battery pack 'survive'
keeping the 732A 'hot'?  Is the external pack recharged at Fluke or does it
have to make a round trip on the initial charge?  Once I am convinced my
unit is stable (which will probably be another six months or so, after I get
my 3458A's re-calibrated by Agilent), I hope to be able to send it to Fluke
for calibration.

Fluke made a transit case (732A-7002) and a Battery Charger and Auxiliary
Battery Case (732A-7003).  However, I have never seen a picture of either of
these.  Does anyone have any information on these?

How did you make your case?  Did you include a charger?  Combination of
battery pack and shipping container or separate battery pack and shipping
container?  

I was thinking of building a case with built-in charger, fuse, and AC
connector and cord such that when the unit arrived at the CAL facility all
that would be needed would be to plug it in and allow the external battery
pack to recharge while the unit being calibrated was plugged in, recharge
the internal batteries, and calibrated.  Or does the 732A also charge the
external battery pack along with the internal batteries?

The connector you need (complete with female contacts) is a Hypertronics P/N
D01PB306FSTAH and is in stock at Kensington Electronics at $8.96 each (plus
tax and shipping).  Only problem is their $50 minimum order.

The 'shell' only is P/N D01PB306NT and the female contact is P/N
YSK006-010ANH (three needed).

http://ecommerce.keiconn.com/hypertronics/D01PB306FSTAH

I ordered two of the connectors from Fluke using a P/N that one of the Fluke
folks in their eCal facility gave me, noting that someone else had asked the
same question a couple of weeks earlier, with Fluke Item# 2181497, described
as '100-166, PLUG - MALE, HYPERTRONICS'.  They were $12.31 each (plus tax
and shipping) and arrived as the shell only, no contacts.

If Fluke solves their supply chain problem, I sure would like to get the six
female contacts I need to make my connectors 'complete'.  When I got on the
phone with Fluke, I could never find anyone that had any knowledge about
this.  Is there anyone there I should ask for that might understand my
question? 

I look forward to your posting the update from Fluke.

Thanks.

Joe


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Re: [volt-nuts] A Fluke 732A: Return it or keep it?

[J. L. Trantham]

Michael,

I would recommend you download the manual if you have not already done so.
(Sorry, just noticed you had looked at the manual.)

I don't think you are going to have enough resolution with the 3457A to
characterize the 732A, other than a rough idea of stability.  You will need
a 3458A, a Solartron 7081 or some other 8 1/2 digit DMM.

The unit uses four 6 V SLA batteries that are relatively cheap.  I ordered 8
of them since shipping was the same, whether I got 4 or 8.  Unless they were
recently replaced, you will need to replace them.  The 'In Cal' light needs
to be 'reset' after the unit is powered up, stabilized, and calibrated.  It
remains on as long as there is continuous power applied to the unit, either
from AC, the battery pack, or an external battery attached to the connector
on the back.  I have a spare connector, yours for cost plus shipping, if you
need one.  Two others on the list have sent me the money for one but work
has really interfered with my life this week and I have not yet shipped
them.  It will be tomorrow.  (Sorry, guys, my apologies.)

The batteries I ordered are these:
http://www.batteryclerk.com/store/p/80492-Panasonic-LC-RB064P-Sealed-Lead-Ac
id-AGM-VRLA-Battery.html  $5.69 each plus shipping.

If power is lost, power must be re-attached and the 'In Cal' light 'reset'.
The light is 'reset' by connecting the negative terminal to a spot in the
'reset' hole just below the 'In Cal' light.

If the battery charge light is not on, and the unit is plugged in, the
batteries are either completely charged, not connected, dead, or there is a
problem with the charger circuit.  My bet is a battery issue since I bet you
had to plug in the unit to get it to work.

There is a multi-turn pot inside each of the three holes and they are
difficult to get to but can be seen if you have a flashlight to shine in
essentially parallel to your line of sight.  If the 10 V can't be brought to
exactly 10.000 V, there are 'jumpers' under the top layer of insulation
for the 'heated unit' that can be adjusted to bring it 'in range'.  At least
I was able to bring mine 'in range' and 'calibrated' against my Agilent
Cal'd 3458A.  Mine has been on continuously now for about 2 months.  I
'calibrated' it after it was on for about a week.  It now reads about
9.920 V and seems extremely stable (3458A with NDIG=8 and NPLC=60).  I'm
thinking of 're-calibrating' it and see how close it will stay to 10.000
VDC.  I think it will be more stable the longer it is on.  I have no idea of
how long it was off before I turned it on.

The schematic of the A5 Reference PCB Assembly shows the calibration
adjustments and the drawing of that assembly shows the location of the
adjustments.  They are deep inside the unit.  You'll need a small flat
bladed tool, a flashlight, and probably a magnifier.  I used a length of 12
ga. copper wire with one end flattened to make a screwdriver.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Michael Hong
Sent: Friday, March 07, 2014 6:19 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] A Fluke 732A: Return it or keep it?

Hi nuts,
This is my first message. Just reading the posted messages is a big learning
to me so I didn't post but instead trying to read all.

Here is my issue.

I received a Fluke 732A yesterday which was purchased from an eBay seller.


(1)
I plugged in and started measuring the 3 voltages and thermistor resistance
value.
After about 2 hours later all 3 voltages were stabilized and thermistor
value stabilized after 24 hours.

All voltages and thermistor values were measured on a HP 3457 which was
calibrated and certified by a local cal lab 10 months ago. Here is how I
measure: After changing the connection to a different voltage I wait 30
second. I start STAT and wait 1 minute and R MEAN.

10V  (10.000360 36.0ppm, 360uV)
1V    (1.383 38.3ppm, 38.3uV)
1.018V  (1.0180200 20ppm, 20uV)

According to the manual adjustable(calibration) ranges are:
10V 5ppm 50uV
1V   5ppm 5uV
1.018   50ppm 50uV

So obviously either 732A or 3457A is wrong.
I tried to contact the person who calibrated the HP 3457A. No response. 

(2)
No light on BTRY CHG and IN CAL
Rear panel Battery Operation switch is on.

(3)
Front panel calibration hole
I put a thin flat blade driver into the holes. I couldn't feel anything
until 4 1/4 inside where I felt something but not the potentiometer.



I offered to the seller that if I find the 732A is no problem but only
requires the new battery, refunding $150 for the battery will close the
deal. All other case, I return the item. 

He responded Just return it.

My questions:
(1) Which one is wrong the DMM or 732A?
(2) What is the cheapest battery replacement cost?
(3) Were the calibration mechanism removed or they are there? In manual I
couldn't find any detailed description or diagram of it.

Last, I paid $650 plus $35 shipping. Do you think it is worth 

Re: [volt-nuts] A Fluke 732A: Return it or keep it?

[J. L. Trantham]

Michael,

Definitely need to keep it on, ship it hot, and have an external battery
pack attached.  IIRC, the internal batteries are good only for about 4
hours.  I have not tested that though.  I think I read this in the manual or
one of the list members mentioned it.  That's why the connector is on the
back, to allow attaching an external battery pack for longer duration away
from AC power.

I would love to get mine calibrated with Fluke but I think I want to wait a
few more months before undertaking this.  Any suggestions from the group on
how long to leave it on?  What 'drift' rate I would want before concluding
it is 'stable'?  I have a 3458A Opt 002 that I can use to track it with and
another 3458A that I can track the thermistor with.

Removing the battery pack is easy, just remove four screws and slide it out.
Certainly worth doing if you are going to keep it.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Michael Hong
Sent: Friday, March 07, 2014 10:22 PM
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?

Thank you all for your concerns.

I will reply out of order, sorry.

IN CAL right came on as I poked(turned) with a slim screw driver. Yes, I
know it supposed to be on after calibration.

AC PWR light turned and stayed on ever since I plugged in the main
yesterday.

When I pulled out the main plug as you said, voltages went down immediately.
Probably the battery is completely gone.

I have been asking quote on this standard from Fluke down to local no name
guy long before I buy it.
I have no intention of calibrating this by myself. That defeats the purpose
of the purchase.
Because it will be my primary standard.

I just wanted to turn slightly to both directions to see if the
potentiometer is working since the 732A's volts looked out of ranges. I
calibrated 8 720As with Nanovolt Null meter and Keithley 155 last week, so I
have no fun left to turning the small thing.

The battery is big concern to me. When I called Fluke, one of the rep said
it should be shipped to them hot Because 732A's battery life is very
limited, it should be shipped using Morning Service. I was going to call
FedEx if they have 12 hours service. And I belive most cal lab require the
732A to be delivered hot. The manual says so.

Thermistor value is now 4470.1132 ohm It changes less than 50mmohm/hour now.

Once I purchase one more 732A, I will experiment how  close it come back to
before turn-off value.

Again thank you all.

Best Regards,

Michael
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Re: [volt-nuts] Question for Fluke 732A owners

[J. L. Trantham]

Oh!!  THAT's what they mean by 'male' and 'female'.  I get it!   :^))

My 732A has male pins on the battery module and female sockets on the mating
connector/plug.

BTW, the mating connector is not easy to find.  Several phone calls to Fluke
led me to Fluke Item Number 2181497, Description: 100-166, PLUG - MALE, H.
I ordered two but all that arrived was the shell, no contacts.  I tried
calling Fluke but was unable to find anyone that had a clue about the plug
or it's contacts.  Perhaps I'll try again when I get some spare time to
spend  another hour on the phone.

An effort with the Hypertronics website led to P/N D01PB306FSTAH which is
the mating plug for the Fluke 732A, contacts and all.  The plug is composed
of two components:  HYP D01PB306NT, PLUG, 3P BLACK, and HYP YSK006-010ANH,
SOCKET, SOLDER CUP 50 UIN, but it is ordered with the P/N listed.

I found them at Kensington Electronics in Austin, TX, with a minimum $50
order.  I ordered 6 after reviewing the specifics with the sales person who
confirmed that I had the correct part number.  They work perfectly.  I have
some spares if anyone is interested.

If you wanted male contacts for the mating plug for the 732A, as best I can
tell, the P/N would be D01PB306MSTH.  The 'TAH' relates to 50 uin gold over
nickel plating over female sockets and the 'TH' relates to 50 uin gold over
nickel plating over male pins.  A little time with the data sheet for the
Hypertronics connectors should make it all clear.

Joe




-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Charles Steinmetz
Sent: Wednesday, February 26, 2014 4:47 PM
To: VoltNuts
Subject: [volt-nuts] Question for Fluke 732A owners

Fluke used two different connector schemes for the DC input on 732A battery
packs.  The oldest units have a pair of banana jacks, and later units use a
3-pin connector made by Hypertronics.  My question concerns only the latter
(732A battery packs with the Hypertronics connectors).

The Hypertronics contacts are interchangeable between the panel mount
connector body and the plug body.  It is customary to build the panel mount
connectors with female contacts, and the plugs with male contacts.  However,
it appears that Fluke may have made at least some 732A battery packs with
male contacts in the panel mount connectors.

I'd be interested to know what is out there in the field.  If you have a
732A battery module with the Hypertronics 3-pin connector, could you please
look at the connector and let me know if the contacts are male or female?

Just to be painfully clear, I'm referring to the gold-plated metal contacts
only, not to the black plastic parts of the connector.  The gold-plated
metal contacts can be male (i.e., the metal part you can see is a solid pin)
or female (i.e., the metal part you can see is a hole that will accept a
pin).

Thank you,

Charles

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[volt-nuts] Fluke 732A Questions

[J. L. Trantham]

I just spoke with Fluke about calibration options for the 732A and how to
connect an external battery pack.

 

There are three calibration options:

 

1.Z540  $700

2.   Accredited  $1000

3.   Primary Standards Lab   $1485

 

These are described on their website:
http://us.flukecal.com/support/calibration-services/electrical-rf

 

The Fluke part number for the male plug to connect to the socket on the back
of the battery module, 732A-7005, is 2181497 and is available for $12.75.  I
ordered two.  With that, I can construct a transit case with room for
external batteries and be able to ship it overnight to Fluke for
calibration.

 

The folks in calibration service suggested I send them an email requesting
the value of the Thermistor and whether old/original calibration
certificates might still be available and they would forward it to the folks
that, at one time, were in charge of keeping that information.  At one time,
that information was kept but, according to them, no one wanted it.
Therefore, they no longer keep that information.  

 

However, perhaps it might be available for this 'vintage' equipment.

 

We'll see.

 

Thanks to all for their help.

 

Joe

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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Just noticed the 'banana plugs' mounted on the chassis to 'align' the
battery module.  Duh.  Makes perfect sense.

Also, thanks for the Pomona recommendations.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Bill Gold
Sent: Wednesday, January 01, 2014 10:38 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Joe:

A correction on the dropout voltage when the In Cal light goes out, I
found my notes and it is 21 volts instead of 22 volts.  The way I did this
was to remove the battery pack, AC voltage and then just feed in a power
supply where the battery pack would have delivered it's voltage to the
back-plane mother board.  Then I just reduced the voltage until the light
turned off.  So that means that Fluke was following the battery
manufacturers specs of 5.25 volts at the end of the discharge curve.

The banana jacks on the battery pack have two jobs.  One is to provide a
very good chassis ground to the battery pack and the other is probably to
guide the pack accurately into the mother board.  One other thing I have
found out the hard way is that the holes in the top plate of the battery
pack where the battery terminals come through are very close to the battery
terminals and can short out to the chassis.  I have made the holes a LOT
bigger to avoid this problem.  This really depends upon the brand of
batteries you are using but after having to repair the regulator board I
would rather be safe than sorry.

I have 6 Pomona 1756-48 low thermal leads for when I need to be careful
with thermals.  I also have made my own low thermal(I think) using
Pomona 4892 gold plated double banana plugs and Belden 9272 twisted pair
twinax, using a Pomona 1825 for the ground lead.  If I need single banana
plugs to connect to the 732A I use Pomona 4897 gold plated.  I know that
this isn't the best possible low thermal because the wire is tin plated but
I have looked and I can't find a good source of bare copper twisted pair
shielded wire.  When I am making measurements with the home made cables I
just wait a few minutes for the thermals to settle down.  Why Belden 9272?
It was the best choice from what was available at work.  From what I have
seen Pomona was acquired by Fluke and makes special low thermal cables for
Fluke that are not available through the Pomona catalog.

When you find out from Fluke what services they offer and prices please
let all of us know.

Bill

- Original Message -
From: J. L. Trantham jlt...@att.net
To: 'Discussion of precise voltage measurement' volt-nuts@febo.com
Sent: Tuesday, December 31, 2013 5:13 PM
Subject: Re: [volt-nuts] Fluke 732A Questions


 Bill,

 I have yet to put my 732A though it's paces but I could connect an
external
 power supply, disconnect the AC supply and the battery module and slowly
 decrease the supplied voltage and see what happens when.

 I'll try your measurement algorithm for the battery to see when the 'IN
CAL'
 LED goes out and what the current draws are.  If the measured voltage at
J10
 is 27 V, then the actual battery voltage should be about 27.6 V,
accounting
 for the diode in the circuit (unless the current draw during measurement
is
 so low that no voltage drop occurs across the diode).

 I found the NIST/NBS Tech Note easily.

 I think if I decide to send it out for calibration, I'll use Fluke, if
they
 still calibrate the unit.  I'll call them later this week of next week to
 see what services/accessories they might still have available.

 Yes, I wound up with the 735C.  It was easy to replace the NiCd battery
pack
 and bring it 'on scale' by adjusting the 'jumpers' and the front panel
 adjustment.  I now only have to deal with the periodic 'NO CAL' LED
 indication.  I need to study the 732A manual then take a close look at the
 735C to see how it works on it.

 This also brings up the question of 'low EMF cables' for accurate
 measurement.  I have a Fluke 720A K/V Divider on the shelf that I have yet
 to bring out to check to see if it is operational.  Another one of those
 'projects' for a later time.

 Where would one look for 'low EMF cables' to be used in precise
measurement
 experiments and what errors might one expect to find using Pomona gold
 plated Banana Plug cables (which is as good as I have at this time)?

 Thanks for the info.

 Happy New Year to all.

 Joe


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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Charles,

I would like to find the mating plug for J10 for several reasons, being able
to get it to calibration being just one of them.  However, I was hoping it
would be good enough to make it to calibration on the internal batteries.

I seem to recall reading that the internal batteries were good for a few
hours but nothing like what the 732B would do, which sounded like the 732B
could make the trip on the internal batteries.

Where did you find the resistance of the thermistor 'as shipped'?  I saw
mention of being supplied to the original owner when shipped as well and I
have had the top cover off and the battery module out to replace the
batteries and found nothing to suggest a thermistor value.  I have also
lifted the top layer of insulation off the oven to move the cal-jumpers but
did not see anything that suggested a thermistor value.

My 'metrology level' standards are my HP 3458A's, calibrated by Agilent, and
Solartron (Ametek) 7081's calibrated by Ametek.  I have been thinking of
getting the 732A calibrated by Fluke but I didn't know if they would still
calibrate the unit.  I wonder if they would have the 'as shipped' thermistor
value on file for my specific serial number?

I, too, read about the stability of the thermistor being the most important
measurement.  That was in the 'change sheets' attached to the manual on
Didier's site.

The 'cal-jumper' was at '40' when I got the unit.  Per my 3458A, I could
only get it down from about +220 uV to about +100 uV with the front panel
adjustment.  By moving the jumper to '20', I could only get it up to about
-12 uV below 10 V by turning the adjustment all the way in the opposite
direction.  However, by connecting jumpers for both the '20' and '10', I was
able to get it at 10 V with the front panel adjustment at about center
position.  I have not 'logged' any values yet but every time I go to the
shop, it is about +/- 1 or 2 uV from 10 V.  I do the 'AUTO CAL' on the 3458A
each morning I go into the shop.  

I measure the resistance with a Fluke 8050A (simply because it is the
closest DMM to the standard) and it is 4229 to 4230 ohms each day.

Interestingly, when I got the 732A, undisturbed Fluke Calibration stickers
were in place over each of the adjustments on the front panel, on a back
screw on the top cover, and 'half' of a sticker on the back over the power
supply module, as if the other half was lost when someone removed the
battery module.  Somehow, I find that comforting, given that it now seems so
stable, making me think it is 'normal aging' that is responsible for the
values I measured rather than a problem with the oven, etc..  IIRC, the spec
is 6 ppm per year for 10 V, or 60 uV per year.  I'll have to look at the
power supply module to see if I can find some date codes but I suspect the
unit is 25 to 30 years old.  Unfortunately, there were no 'dates' on the
stickers to tell when the unit was last calibrated.

I was thinking of sending the 3458A's and the 732A out for calibration
simultaneously and seeing what I find when they get back.  

I'll call Fluke and ask about their Cal services, the plug, and the shipping
case/battery pack issues.

Thanks everyone for very useful information.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Charles Steinmetz
Sent: Monday, December 30, 2013 11:23 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Joe wrote:

Also, how do you get your 732A calibrated?  Do the batteries last long 
enough to ship overnight to a facility?

No -- I assumed that was why you were looking for a battery connector.  You
install an external battery for shipment overnight.  Fluke can supply a
complete external battery with cable and plug ($375, last I knew), or you
can make your own.  I believe they can also supply a shipping container,
which has a dedicated space for the Fluke external battery.  (If you don't
use Fluke's container, build something very sturdy with wood and padding and
with handles that make it hard not to carry it and set it down right side
up.)

I wouldn't have anybody but Fluke calibrate a 732A.  There are 3 levels of
calibration, all with data, from about $700 to about $1500 (the last is
calibration by Fluke's Primary Standards Lab).

As far as thermistor values go, the relevant question is not what is the
value in absolute terms, but rather what is the value in relation to the as
manufactured value, which was provided by Fluke when the unit shipped.
This had been recorded by the original owners of each of my units, and they
are all within 2 ohms of the original value today.

If you do not know the original value, then your original measurement is a
going forward value and it cannot tell you anything about where you are in
relation to  the original manufactured value.  The fact that you had to
change cal jumpers suggests that either the oven temperature has shifted
since manufacture, the reference 

Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

I was afraid of that.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of R.Phillips
Sent: Tuesday, December 31, 2013 7:53 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Joe
Reference the thermistor value and its recorded value - I asked Fluke this
question and the answer was, they did supply the individual 732A's value in
written form to the original purchaser, but unfortunately they did not
maintain a separate record.
Roy

-Original Message-
From: J. L. Trantham
Sent: Tuesday, December 31, 2013 1:22 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Fluke 732A Questions

Charles,

I would like to find the mating plug for J10 for several reasons, being able
to get it to calibration being just one of them.  However, I was hoping it
would be good enough to make it to calibration on the internal batteries.

I seem to recall reading that the internal batteries were good for a few
hours but nothing like what the 732B would do, which sounded like the 732B
could make the trip on the internal batteries.

Where did you find the resistance of the thermistor 'as shipped'?  I saw
mention of being supplied to the original owner when shipped as well and I
have had the top cover off and the battery module out to replace the
batteries and found nothing to suggest a thermistor value.  I have also
lifted the top layer of insulation off the oven to move the cal-jumpers but
did not see anything that suggested a thermistor value.

My 'metrology level' standards are my HP 3458A's, calibrated by Agilent, and
Solartron (Ametek) 7081's calibrated by Ametek.  I have been thinking of
getting the 732A calibrated by Fluke but I didn't know if they would still
calibrate the unit.  I wonder if they would have the 'as shipped' thermistor
value on file for my specific serial number?

I, too, read about the stability of the thermistor being the most important
measurement.  That was in the 'change sheets' attached to the manual on
Didier's site.

The 'cal-jumper' was at '40' when I got the unit.  Per my 3458A, I could
only get it down from about +220 uV to about +100 uV with the front panel
adjustment.  By moving the jumper to '20', I could only get it up to about
-12 uV below 10 V by turning the adjustment all the way in the opposite
direction.  However, by connecting jumpers for both the '20' and '10', I was
able to get it at 10 V with the front panel adjustment at about center
position.  I have not 'logged' any values yet but every time I go to the
shop, it is about +/- 1 or 2 uV from 10 V.  I do the 'AUTO CAL' on the 3458A
each morning I go into the shop.

I measure the resistance with a Fluke 8050A (simply because it is the
closest DMM to the standard) and it is 4229 to 4230 ohms each day.

Interestingly, when I got the 732A, undisturbed Fluke Calibration stickers
were in place over each of the adjustments on the front panel, on a back
screw on the top cover, and 'half' of a sticker on the back over the power
supply module, as if the other half was lost when someone removed the
battery module.  Somehow, I find that comforting, given that it now seems so
stable, making me think it is 'normal aging' that is responsible for the
values I measured rather than a problem with the oven, etc..  IIRC, the spec
is 6 ppm per year for 10 V, or 60 uV per year.  I'll have to look at the
power supply module to see if I can find some date codes but I suspect the
unit is 25 to 30 years old.  Unfortunately, there were no 'dates' on the
stickers to tell when the unit was last calibrated.

I was thinking of sending the 3458A's and the 732A out for calibration
simultaneously and seeing what I find when they get back.

I'll call Fluke and ask about their Cal services, the plug, and the shipping
case/battery pack issues.

Thanks everyone for very useful information.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Charles Steinmetz
Sent: Monday, December 30, 2013 11:23 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Joe wrote:

Also, how do you get your 732A calibrated?  Do the batteries last long 
enough to ship overnight to a facility?

No -- I assumed that was why you were looking for a battery connector.  You
install an external battery for shipment overnight.  Fluke can supply a
complete external battery with cable and plug ($375, last I knew), or you
can make your own.  I believe they can also supply a shipping container,
which has a dedicated space for the Fluke external battery.  (If you don't
use Fluke's container, build something very sturdy with wood and padding and
with handles that make it hard not to carry it and set it down right side
up.)

I wouldn't have anybody but Fluke calibrate a 732A.  There are 3 levels of
calibration, all with data, from about $700 to about $1500 (the last

Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Jeff,

Too late. 

I have already moved the jumpers and adjusted all of the front panel 
adjustments to achieve the desired output voltages.

Since I don't have any 'historical' data about the performance of my specific 
unit, I will 'start from scratch' on the unit I now have.  Whether to send it 
out for calibration or just keep it, adjusted by the 3458A, and watch from now 
on is the issue.

I don't have enough data to decide about long term stability at this point but 
I am gaining valuable information about how long it will last on batteries and 
how to go about preparing it for shipment for calibration if I go that way.

Thanks for the input.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf 
Of jeffh...@comcast.net
Sent: Tuesday, December 31, 2013 5:23 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions



Hi,  



Are you guys adjusting your 732As? 

I have a friend that works in a large CAL lab and he told me to never adjust my 
732As, just compare them. 

They send out their 732 Bs to Fluke but are never adjusted, just compared and 
sent back with current voltage reading ?? 



Thanks - Jeff  



- Original Message -


From: Charles Steinmetz csteinm...@yandex.com
To: Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Tuesday, December 31, 2013 9:56:37 AM
Subject: Re: [volt-nuts] Fluke 732A Questions 

Joe wrote: 

Where did you find the resistance of the thermistor 'as shipped'?  I 
saw mention of being supplied to the original owner when shipped as 
well

It was recorded on the original factory cal certificate.  I have the original 
certificates for two of mine.  The others had rear panel stickers applied by 
their original owner (a cal lab). 

A properly working, good example should hold 0.1 ppm or better year in, year 
out.  I've seen some that do not meet that, but lots of them do.  I'm not aware 
of any other non-JJ standard that can match it, including most 732Bs.  (Some 
folks think 732As are generally better than 732Bs because they are older and, 
thus, more stable because better aged.  I think there is more to it -- many 
732Bs are plenty old enough to have settled down to that level if they are ever 
going to, but even the older 732Bs don't, in general, seem to exhibit quite the 
stability of the 732As.) 

Best regards, 

Charles 



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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Interesting thought.  I love it when guys of that caliber compete.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Tuesday, December 31, 2013 5:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Call Agilent about 3458A calibration then tell them that you really want
your fluke calibrated and see what they will do for you.


On Tue, Dec 31, 2013 at 3:48 PM, John Phillips
john.philli...@gmail.comwrote:

 Any thing you do other than record the current voltage reading will 
 introduce more uncertainty and increase drift unless you have a defect.
 Replacing a defective part will start the aging process over again for 
 that part. Do not change anything if you can help it.

 Agilent is a good cal lab to use as well. They will run it for a few 
 days and take readings a few different times and give you a report.
 Most of the time the battery is not enough to keep the box hot until 
 they plug it in  so they count on warming up a few days.

 Hope that helps.
 John


 On Tue, Dec 31, 2013 at 3:31 PM, Chuck Harris cfhar...@erols.com wrote:

 The obvious reason for that suggestion is the adjustment pot is 
 likely to be noisy and is likely to introduce uncertainty.

 The big question that comes to my mind is if you care about that 
 level of uncertainty, why not replace the pot with a voltage divider 
 made of some low thermal coefficient fixed value resistors?

 -Chuck Harris

 jeffh...@comcast.net wrote:



 Hi,



 Are you guys adjusting your 732As?

 I have a friend that works in a large CAL lab and he told me to 
 never adjust my 732As, just compare them.

 They send out their 732 Bs to Fluke but are never adjusted, just 
 compared and sent back with current voltage reading ??



 Thanks - Jeff

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 --
 John Phillips




--
John Phillips
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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

 of any 732A units and just relied upon the inter-comparison
method to hopefully keep a reasonable value of the Volt.  I have looked
around the South SF Bay Area for a Cal Lab who could Certifiy one of my
units and the only place I could find would be Simco in Sunnyvale.  I will
have to ask them what they charge for a Certitication of a 732A.  The
local Fluke place used to charge $500 but then that was using 732As that
they had sent into Fluke in E  verett WA.  But then since this is just a
hobby anymore I don't need, and didn't need while I was working, the full
blown services and accuracy of Fluke in Everett.  I guess a 732B would be a
way to get all of this but who needs it right now, not me.  Of course I
could always get my own Josephson Junction but then I would be a real crazy
Volt Nut and certifiable at the same time.

I have never even heard about the Fluke 735C until I saw one on fleabay,
and I assume you were the one who bought this when I saw you asking about
schematics.

Happy New Year

Bill   

- Original Message -
From: J. L. Trantham jlt...@att.net
To: 'Discussion of precise voltage measurement' volt-nuts@febo.com
Sent: Monday, December 30, 2013 6:28 PM
Subject: Re: [volt-nuts] Fluke 732A Questions


 Bill,
 
 Sounds like you are further along in the 'volt-nut' process than I am.
I'll
 have to chase down the NIST paper.  I have been very impressed by the
 stability of the 732A and the 735C.
 
 Unfortunately, I don't have any documentation on the 735C and only the
early
 manual for the 732A.
 
 I would be interested in the specifics of the battery check procedure in
 your manual.  Unfortunately, my manual does not have a page 2-9.
 
 I note that there are two banana jacks on the front of the battery module,
 both black, one connected to ground and the other not connected to
anything.
 Any idea of what they are for?
 
 I always like to keep equipment as 'original' as possible.  If I can't
find
 the correct connector, I'll find something similar that will fit in the
same
 hole and use it instead.  We'll see what I hear from Fluke and
Hypertronics.
 
 Also, how do you get your 732A calibrated?  Do the batteries last long
 enough to ship overnight to a facility?
 
 Thanks for the info.
 
 Joe
 
 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
 Behalf Of Bill Gold
 Sent: Monday, December 30, 2013 7:03 PM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] Fluke 732A Questions
 
 Joe:
 
 My 732A units vary in thermistor resistance from 3.408K ohms to 4.514K
 ohms and have been extremely stable to with in +/- 5 ohms for years now.
I
 did measure the oven temperature of the one with the 3.408K ohms just to
see
 what was causing the thermistor resistance to be a little low and came up
 with about 47 degrees centigrade, as best as my equipment would allow me
to
 measure it.  Equipment was a Fluke 80TK thermocouple module, a Fluke 80
PK-1
 thermocouple bead and a HP 3456A DVM.  I put shrink wrap around the bead
and
 then threaded the bead into the temperature oven through one of the
 adjustment holes in the front panel and made sure that it was far into the
 oven, probably around the middle.  Then I checked another unit that read
 4.5K ohms and it read around 43 degrees C so all of that made sense.  I
 believe I saw somewhere that the spec was 45 degrees C +/- 2 C.
 
 I did have to change the jumpers on the Calibration PCB Assembly on
 one of my units so that it would match other 732A units that were In Cal
 and had certified values.  But that unit has since drifted down at a rate
of
 around 1.2 ppm per year which is with in specs but a little more than I
have
 seen from other units.  Recently this unit has suddenly quit drifting down
 and seems a lot more stable now.  That was S/N 459.  I have a S/N
 343 which has been proven rock solid for years now at around +/- .3
ppm
 and just seems to have DC noise stability as it just goes up a little
and
 then down a little and never needed any adjustment.  I also have a S/N
 460 which is extremely stable also.  So I guess that age does seem to
 factor into stability as well as how long they have been powered up.  But
 the only way to insure that you have a good volt is to have at least 4
 units and then inter-compare them periodically following NIST (NBS)
 Technical Note #430.  While 430 was written for Saturated Standard Cells,
 the technique seems to work just fine at 10 volts also.  You can also find
 this measurement technique in the 1st Fluke Calibration - Philosophy in
 Practice book published around 1974.
 
 I gave up on the unobtainium connector on the back of the battery
pack
 very quickly.  I drilled a 1/4  holes on either side of the unobtainium
 connector, after removing it, and used two single miniature banana jacks
to
 allow me to connect to the batteries for the purpose of checking their
 performance as described in the 732A manual page 2-9

Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

I called them this AM and they only had a 'copy' of the manual and not an
original.

If I understand what you are saying, you got a copy as well.

If so, were the 'change sheets' part of the 'copy'?  When I asked about
that, I was told that there were no 'change sheets' in the copy she was
looking at when I called and asked about condition and change sheets.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of T. Micallef
Sent: Monday, December 30, 2013 1:06 PM
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Fluke 732A Questions

My manual came from manualsplus. It was in excellent condition compared to
the ones on eBay. You do have to ask them for a picture of every manual
since they can vary in condition.

I have rescanned the whole manual, which I should have done anyway.
I have two missing pages and I am hopeful the seller will scan them and
forward them to me.

Todd

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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Charles,

I just assumed that it was obsolete.  I'll contact Fluke.

Thanks.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Charles Steinmetz
Sent: Monday, December 30, 2013 5:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Robert wrote:

As Roy has already said, this is a hypertronics 
connector.*   *   *   Sorry, I don't have any, or a cheap source.

The plug that mates with the jack on the back of the newer 732A battery is
Fluke part number 2181497.  IIRC, I paid about $10 each (some years ago)
direct from Fluke.

Best regards,

Charles



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Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Roy,

Thanks for the info.

Looking at the Hypertronics catalog, it would appear that the panel mounted
socket (with male, solder cup, pins) is:

P/N D01EEB306MSUTH

And the mating plug would be:

P/N D01PB306FSUTAH

However, the dimensions are a bit off and the appearance of the panel
mounted socket is not the same as what is on my 732A, J10, on the back of
the 732A-7005 battery module.  My connector is exactly as shown in the
change sheets with a dimension of 0.475 inches side to side and 0.500 inches
top to bottom (as viewed from the back of the unit) rather than 0.512 x
0.512 as suggested in the catalog.

However, the diameter of the mounting hole and the presence of a 'notch'
appears to be as shown in the catalog, thus suggesting that it, indeed, is a
series D01 part.  The diameter of the threaded part of J10 is 0.410 inches
and the catalog calls for a hole diameter of 0.441 inches.

One other observation is the presence of a 'symbol' on the bottom edge of
the socket (as viewed from below) that looks like a stylized 'FRE',  The 'F'
perhaps could be an 'A' and the 'E' perhaps could be a 'B'.  The symbol
starts low and ends low with a 'peak' of the symbol in the middle of the
'R', sort of a 'roof' shape to the top of the symbol and flat on the bottom
of the symbol.

Not sure what that means but I have a picture of it if anyone thinks it
would help.  It does not look like the stylized 'H' symbol shown in the
Hpertronic catalog.  Perhaps the company was something else before they
became Hypertronics.

I looked through the change sheets for the 732A and could find no mention of
the value of the thermistor resistance at temperature, only comments about
what its stability should be.  Knowing that you have a value in the mid 4K
range is reassuring.  My S/N starts with 3.

Right now, it indicates 10.005 VDC on the 3458A and 4230 ohms on the
Fluke 8050A.

Thanks for your help.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of R.Phillips
Sent: Sunday, December 29, 2013 8:40 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 732A Questions

Hi Joe
I also obtained a Fluke 732A back in October last, and I have fitted a new
set of SLA batteries and it is working just fine - I am still very impressed
by its accuracy and stability, and its build quality.
First, the external 3-pin power socket is a HYPERTRONICS 'D' type connector
(female) type 100-166 - but I have not found one to date !
I also expected the temperature monitoring thermistor to give a 3 to 4 K
ohms, as indicated in the manual P/N 645051 dated May 1983 - but I guess
that you have a later model as I do, mine being serial # 4845***, some
modifications were made,and I understand that this included a change of
thermistor, so the standard reading is in keeping with your result. My unit
gives a very stable 4.520 K ohms, being between 4.52080 and 4.52090 K ohms. 
Judging by your findings, you are also using the 1983 copy of the User
Manual - we could both use a more up to date issue.
I am awaiting the repair of my 3458A - so I am having to rely upon a
recently calibrated Keithley 2015 and my good old 3456A - but they both give
very impressive results - The Keithley giving 1.07 volts for the 1 volt
output, and 10.0 volts for the 10 volt output (how I miss that final
digit).
Looking forward to your further results and any other owners comments.
Best regards

Roy


-Original Message-
From: J. L. Trantham
Sent: Saturday, December 28, 2013 10:51 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] Fluke 732A Questions

I have reviewed the prior postings on Volt-nuts (a very rewarding review,
BTW)) regarding the 732A and have two questions:



1.Has anyone determined the part number, or a source, for the mating
plug to J10, the external power connector for the 732A-7005 battery pack?  I
noted some postings recently about this but did not find a definitive
response regarding the identity of this plug.  The alternative would appear
to be a complete replacement of J10 and its plug, as long is it all fits in
the opening in the panel.  I hate to 'bore holes' in vintage equipment.

2.   The oven thermistor in my 'new to me' unit measures 4229 ohms (+/-
an ohm or two) after the unit has warmed up for a week or so.  I note the
manual refers to 3K to 4K for the value of this thermistor when the unit is
'stable' as well as other's posting values in the mid 3500's ohms for their
units.  Should I be concerned?  The unit seems to be stable to within about
2 uV over about a week (as measured by my 3458A - see below).  Should I open
the unit and try to measure the oven temperature or just be satisfied that
the unit seems to be working?



I had to replace the four 6V 4AH SLA batteries and they charged up
appropriately as judged by the front panel LED's.  I had to remove the
'jumper' for the '40' option on the A7 board and connect the jumper to the
'20

Re: [volt-nuts] Fluke 732A Questions

[J. L. Trantham]

Todd,

Very good information.

Sounds like we are getting close to the correct P/N for the mating plug for
the socket.

My 732A has only a single transistor mounted to the frame from the A4
Regulator Assembly, in the position of Q4, and the resistance is 4230 ohms
after the unit is 'warmed up' and stable.

I recently bought a manual as well but it did not have any 'update sheets'.
I would love to have a copy of your 'update sheets'.

I did a 'clean up' of the update sheets on Didier's site and can send them
to anyone that wants one.

I printed the .PDF from the Fluke site and added the 'cleaned up' version of
the update sheets and it makes a very nice manual.  I would love to add the
other sheets to this.

I also have a 735C that is very similar to the 732A but lot's of mechanical
differences.  It has two transistors on the Regulator Assembly, presumably
A4 and Q4 and Q14.  I do not have a manual for the 735C. 

It's thermistor value is in the mid 3K range.  It, too, is very stable and
has many similarities to the 732A but has recently developed a 'new
problem'.  The 'NO CAL' LED comes on after a few days for no apparent
reason.  I need to open it up again and take a look at that circuit to see
what the problem is.

On the 732A, the 'IN CAL' LED is continuously lighted when there has been no
power interruption.  On the 735C, the 'NO CAL' LED illuminates when power is
restored after a power failure.  

I replaced the NiCd battery pack and all seems to be well but the 'NO CAL'
LED comes on after having been reset (by inserting a copper wire in the
'adjust' opening).  I wonder if my 'reset' process is the problem.  On the
732A, you connect to the negative terminal then touch the 'pad' inside the
'RESET' opening.  There is no such 'RESET' opening on the 735C.  Just
placing the wire (that I use to adjust the 10 V adjustment) inside the
adjustment opening and aiming to the side would reset the LED.

Happy to help with the scanning of the manual and update sheets if needed.

Thanks again for the info.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of T. Micallef
Sent: Sunday, December 29, 2013 6:05 PM
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Fluke 732A Questions

Joe,

I have the external battery pack (732A-7003) that I picked up a while ago.
It is indeed the D01 connector. It is printed clearly on the outside edge
along with the three letters that look like ARB.

The company's website states they are now owned by Smiths Connectors and the
connector is part of Hypertac. No list of distributors was found on the
website.

I found a seller Astrex Electronics, but they do not have a price listed for
the female version, just the male. I searched for D01P306FSTAH. This is the
female plug with solder cups.

To date, I have reconditioned three 732A's and they have been operating fine
with little issues, except when I lost power for an extended time and two
batteries in one of the packs died. All four were replaced and they have
been working fine.

The two older 732A's have thermistor values in the 3k-4k range. The newer
unit (based on the newer heater rev) is around 4.25K.

All three had their potentiometers changed on the regulator and
pre-regulator boards. The datecodes on all appeared to be from 1985. The
parts list must have been updated as some of the pots did not have the same
value as the ones installed. I cannot remember which ones were different. I
did not see a mention in the change/errata.

Also, I had to remove the reference ovens to repair broken 10V
potentiometers, as someone had broken one (free spinning) and another unit
appeared to have a noisy wiper so it was replaced as well. The 1V and 1.018V
pots were not changed. The third 10V pot was replaced because I had success
with the other two and it was much easier the third time around. The jumpers
on the all the A7 boards were adjusted.

I highly recommend checking the inline fuse to the heater if you suspect it
is not working. You can find it tucked inside behind the oven. It should be
covered in heat shrink. 

Lastly, there was a rev done that does not appear in the downloadable users
manual on Didier's website.  It appears the heaters were separated into two
groups of two instead of one group of four. Some of the parts were mounted
under the oven assembly on the A8 Preheater PCA. If you look at the A4 board
from the top, you will see either one or two transistors mounted to the
frame (Q4,Q14). If you see only one (Q4), chances are you have the newer
rev.

I bought the manual recently and just noticed these revs were in my book.
I will try and scan the extra info and upload them.

Todd




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[volt-nuts] Fluke 732A Questions

[J. L. Trantham]

I have reviewed the prior postings on Volt-nuts (a very rewarding review,
BTW)) regarding the 732A and have two questions:

 

1.Has anyone determined the part number, or a source, for the mating
plug to J10, the external power connector for the 732A-7005 battery pack?  I
noted some postings recently about this but did not find a definitive
response regarding the identity of this plug.  The alternative would appear
to be a complete replacement of J10 and its plug, as long is it all fits in
the opening in the panel.  I hate to 'bore holes' in vintage equipment.

2.   The oven thermistor in my 'new to me' unit measures 4229 ohms (+/-
an ohm or two) after the unit has warmed up for a week or so.  I note the
manual refers to 3K to 4K for the value of this thermistor when the unit is
'stable' as well as other's posting values in the mid 3500's ohms for their
units.  Should I be concerned?  The unit seems to be stable to within about
2 uV over about a week (as measured by my 3458A - see below).  Should I open
the unit and try to measure the oven temperature or just be satisfied that
the unit seems to be working?

 

I had to replace the four 6V 4AH SLA batteries and they charged up
appropriately as judged by the front panel LED's.  I had to remove the
'jumper' for the '40' option on the A7 board and connect the jumper to the
'20' and '10' options (total of '30') in order to get the unit to adjust to
10.000 VDC on my 'Agilent In Cal'd' 3458A.  

 

The need to change the jumpers, perhaps, could be just an ageing issue or,
on the other hand, a 'temperature' issue with the oven.

 

Should I open the unit and directly measure the temperature (supposedly
about 48 degrees C) or just be satisfied with what I have?

 

My recently added 735C also needed moving some 'jumpers' in order to get it
'on scale', as determined by my 3458A, although it's thermistor measures
about 3330 ohms (after being on for several weeks).

 

Thanks for everyone's help.

 

Joe

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[volt-nuts] Fluke 735C - Follow Up

[J. L. Trantham]

Thanks to everyone for their thoughts about the 735C 10.0 VDC standard.

 

I cleaned up the 'corrosion', rebuilt the NiCd battery packs, and plugged it
in.  It measured about 10.00010 VDC after being on for 24 hours or so.

 

I reviewed the manual for the 732A and found quite a similarity, including
the resistor 'decade' of 2K, 1K, 500, 250, and 125 ohm resistors to select
from to achieve calibration.  On the 732A, these are brought out to a
separate (sort of external) PCB to make selection easier.  However, on the
735C, all are mounted on the 'oven unit PCB' and I had to open the oven
several times in order to come up with the correct combination of resistors
in parallel to achieve calibration.

 

I used my recently Agilent Cal'd 3458A and was able to adjust the 'CAL' pot
on the front panel (R20 per the 732A schematic) to bring it 'on scale'.
Looking at the output, it seems to be +/- 2 uV when watching it over about a
week.  Amazingly stable, compared to my 731B's.  I wound up using the 125,
250, and 1K ohm resistors in parallel to get the 'CAL' pot to bring on scale
as measured by the 3458A.  The 'TH' resistance is about 3.3307 K ohms and
very stable.

 

The 732A has a front panel LED that illuminates when the unit is 'IN CAL'
while the 735C has an LED that illuminates when there is 'NO CAL'.

 

To get the 'NO CAL' LED to go out, I just used a copper 14 ga wire as the
'twiddler' and when I touched the internal 'Oven' case (likely shorting it
to the front panel case) the LED went out (after everything had warmed up
for a day and adjusted to 10.000 VDC).  The 'NO CAL' LED has been out
now for about a week and looking at the 3458A it is about +/- 2 uV from
10.000 VDC.

 

I have some pictures of the 'innards' of the oven if anyone is interested.

 

The NiCd's (2800 mAH compared to 2500 mAH original batteries) seem to power
the unit for only about 3 hours.

 

Joe

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Re: [volt-nuts] VS330

[J. L. Trantham]

Worked fine with Win7Pro and Adobe Reader X.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Didier Juges
Sent: Saturday, September 21, 2013 5:13 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] VS330

I do not use Acrobat, but the manual opens fine in the Fox it Reader

Didier KO4BB

RF PRECHTL  K7DFW k7...@clatskanie.com wrote:





Downloaded this pdf from KO4BB and my Adobe reader 6.0.6 - 01/08/2007 
claims it is damaged and not capable of opening.


Is this a case where Adobe is not backwards compatible and the KO4BB 
Adobe being too new for my
2007
edition?


Rolynn

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--
Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other
things.
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Re: [volt-nuts] HP 3458A repair.

[J. L. Trantham]

I agree with your assessment of an 'old' meter being more desirable.

I would recommend a conversation with Gary Bierman if you have not already
done that.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 10:45 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.

The meter will be here in a few days. I did buy the ram. As far as the meter
age goes, unless it is a very old hardware revision, I would rather have an
old meter because it is more stable. That is until it brakes.

I do have before and after readings and the 4 readings are the only ones
that failed. The after readings are better than the before readings.
Because the 8 and 10 MHz failed we did not get a certificate but we do have
a good limited calibration up to 2 MHz. Just no official cal.

The cal we wanted was $1600. We will still have to pay that after the
repair.
From what I can tell they did not run SCAL or the before/after readings
would not have matched. Like they really did not run after readings or there
would have been some mismatch.





On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jlt...@att.net wrote:

 John,

 Can you give us more information?  Serial number, Rev. number, CALNUM?  
 How much to invest will be determined by age and other condition.

 It doesn't sound like a simple CALRAM issue but changing the CALRAM is 
 relatively easy.  I removed all three DALLAS chips in mine and 
 installed sockets.  The CALRAM can be read with a chip programmer and 
 the data written to a new DALLAS chip.

 I would also call Gary Bierman at the Loveland Cal Lab and have a long 
 talk with him.  He has a lot of insight into these meters and 
 generally prefers to do a component level repair rather than an 
 assembly level repair.  The charge sounds like their standard repair 
 charge, no matter what the problem is, and includes a 'fresh 
 calibration' along with a warranty, a year I think, but Gary will be able
to answer that question.

 Also, once you get the meter calibrated by Agilent (and thus prove it 
 is functioning normally) it will be eligible for their 'repair agreement'
 which
 is $178.68 per year.  I would consider buying a 5 year agreement after 
 the repair.

 Good luck.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of John Phillips
 Sent: Tuesday, September 17, 2013 3:36 PM
 To: Discussion of precise voltage measurement
 Subject: [volt-nuts] HP 3458A repair.

 Hi,
 I have a 3458A that we sent to Agilent for calibration which it failed.
 Before we sent it we calibrated it and it looked good to us. The 
 infor. we revived led us to believe that the cal memory may have caused
the failure.
  We ask that it be sent buck to us and paid half the cal charges 
 (about
 $800) insted of the $2660.64 they wanted to repair it. We were just 
 going to repalce the ram in try again.
 When we got the meter back it came with befor and afer data Like 
 before 10 volts read 9.957 and after it read 10.9 so they did 
 something or the meter drifted that much.
 The problem is  0.1 volt and 1.0 volts failed at 8 and 10 MHz but 
 passed at
 4 MHz.
 4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 
 volt reads 0.085712 Lower Limit is 0.0959
 2
 0
 FAILED
 10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED

 4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt 
 reads
 0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower 
 Limit is 0.84900 FAILED

 The AC after readings are the same. I do not see how AC after could be 
 that identical even if they did not try to calibrate it. Did they just 
 copy the before data and call it after data?

 My best guess is that if the 4 MHz is in and the higher frequencies 
 are not the meter requires some kind of mechanical adjustment to get the
frequency
 response   withing spec or the AC board needs to be repaid.

 Are they charging a standard repair charge to do a calibration? I do 
 not see changing the memory to fix this.

 Where would you go from here if this was your meter?


 --
 John Phillips
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Re: [volt-nuts] HP 3458A repair.

[J. L. Trantham]

You have to remember he is employed by Agilent and he has considerable
energy invested in this meter.  I'm not convinced he thinks moving
manufacturing to Malaysia was a smart move given the extreme performance
specs for this meter and the extreme performance specs required for the
parts that went into the meter.

It might be that he was giving you some hints about what to change to again
see if it would meet spec.

What 'standards' do you have that might address the scales in question?  Do
you have another 'calibrated' meter that you might use as a 'transfer
standard'?

IIRC, they call for an HP 3325A as the source for the AC scales.  I don't
have any 'thermal standards' but I did use an HP 3326A as the source and an
Ametek calibrated Solartron 7081 as the 'transfer standard' on the 3458A
that I calibrated but the two middle AC scales (can't recall right now as I
am OOT) did not meet spec in the 'as found' category but were able to be
calibrated by HP.  All I got was the 'Agilent Cal' for about $500 or so.  I
have since returned it to Agilent for 're-cal' just over a year later and it
was still 'in spec' 'as found'.  I also got the 'Repair Agreement' after it
was calibrated.  That way, if it fails in the next 5 years, it will be
repaired and calibrated 'no additional charge'.

So, if you have any insight from the conversation with Gary, you might try
changing the appropriate parts and see what you get.

I now have a Fluke 5100B and 5200A along with my 'in cal' 3458A and happy to
help in any way I can.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 3:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.

I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement.  The only problem seems to be the amplifier/attenuator
 flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as if
we ever did.



On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jlt...@att.net wrote:

 I agree with your assessment of an 'old' meter being more desirable.

 I would recommend a conversation with Gary Bierman if you have not already
 done that.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
 Behalf Of John Phillips
 Sent: Wednesday, September 18, 2013 10:45 AM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] HP 3458A repair.

 The meter will be here in a few days. I did buy the ram. As far as the
 meter
 age goes, unless it is a very old hardware revision, I would rather have
an
 old meter because it is more stable. That is until it brakes.

 I do have before and after readings and the 4 readings are the only ones
 that failed. The after readings are better than the before readings.
 Because the 8 and 10 MHz failed we did not get a certificate but we do
have
 a good limited calibration up to 2 MHz. Just no official cal.

 The cal we wanted was $1600. We will still have to pay that after the
 repair.
 From what I can tell they did not run SCAL or the before/after readings
 would not have matched. Like they really did not run after readings or
 there
 would have been some mismatch.





 On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jlt...@att.net wrote:

  John,
 
  Can you give us more information?  Serial number, Rev. number, CALNUM?
  How much to invest will be determined by age and other condition.
 
  It doesn't sound like a simple CALRAM issue but changing the CALRAM is
  relatively easy.  I removed all three DALLAS chips in mine and
  installed sockets.  The CALRAM can be read with a chip programmer and
  the data written to a new DALLAS chip.
 
  I would also call Gary Bierman at the Loveland Cal Lab and have a long
  talk with him.  He has a lot of insight into these meters and
  generally prefers to do a component level repair rather than an
  assembly level repair.  The charge sounds like their standard repair
  charge, no matter what the problem is, and includes a 'fresh
  calibration' along with a warranty, a year I think, but Gary will be
able
 to answer that question.
 
  Also, once you get the meter calibrated by Agilent (and thus prove it
  is functioning normally) it will be eligible for their 'repair
agreement'
  which
  is $178.68 per year.  I would consider buying a 5 year agreement after
  the repair.
 
  Good luck.
 
  Joe
 
  -Original Message-
  From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com]
  On Behalf Of John Phillips

Re: [volt-nuts] HP 3458A repair.

[J. L. Trantham]

Forgot to ask.  

Do you have the CLIP?

Joe


-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Wednesday, September 18, 2013 3:51 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3458A repair.

I talked with Gary... it sounded more like a sales pitch like they replace
relays before they failed. The date code on the cal ram is 6 years past
replacement.  The only problem seems to be the amplifier/attenuator
 flatness. He said this could be caused by caps aging and changing value.
They tried calibrating the AC but it did not come withing spec so they did
not update the as left data... I think if they are going to send the as
left data it should be real as left or blank. This meter looks like a good
meter for what I will use it for so we will not use the AC above 2MHz as if
we ever did.



On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham jlt...@att.net wrote:

 I agree with your assessment of an 'old' meter being more desirable.

 I would recommend a conversation with Gary Bierman if you have not already
 done that.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
 Behalf Of John Phillips
 Sent: Wednesday, September 18, 2013 10:45 AM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] HP 3458A repair.

 The meter will be here in a few days. I did buy the ram. As far as the
 meter
 age goes, unless it is a very old hardware revision, I would rather have
an
 old meter because it is more stable. That is until it brakes.

 I do have before and after readings and the 4 readings are the only ones
 that failed. The after readings are better than the before readings.
 Because the 8 and 10 MHz failed we did not get a certificate but we do
have
 a good limited calibration up to 2 MHz. Just no official cal.

 The cal we wanted was $1600. We will still have to pay that after the
 repair.
 From what I can tell they did not run SCAL or the before/after readings
 would not have matched. Like they really did not run after readings or
 there
 would have been some mismatch.





 On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham jlt...@att.net wrote:

  John,
 
  Can you give us more information?  Serial number, Rev. number, CALNUM?
  How much to invest will be determined by age and other condition.
 
  It doesn't sound like a simple CALRAM issue but changing the CALRAM is
  relatively easy.  I removed all three DALLAS chips in mine and
  installed sockets.  The CALRAM can be read with a chip programmer and
  the data written to a new DALLAS chip.
 
  I would also call Gary Bierman at the Loveland Cal Lab and have a long
  talk with him.  He has a lot of insight into these meters and
  generally prefers to do a component level repair rather than an
  assembly level repair.  The charge sounds like their standard repair
  charge, no matter what the problem is, and includes a 'fresh
  calibration' along with a warranty, a year I think, but Gary will be
able
 to answer that question.
 
  Also, once you get the meter calibrated by Agilent (and thus prove it
  is functioning normally) it will be eligible for their 'repair
agreement'
  which
  is $178.68 per year.  I would consider buying a 5 year agreement after
  the repair.
 
  Good luck.
 
  Joe
 
  -Original Message-
  From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com]
  On Behalf Of John Phillips
  Sent: Tuesday, September 17, 2013 3:36 PM
  To: Discussion of precise voltage measurement
  Subject: [volt-nuts] HP 3458A repair.
 
  Hi,
  I have a 3458A that we sent to Agilent for calibration which it failed.
  Before we sent it we calibrated it and it looked good to us. The
  infor. we revived led us to believe that the cal memory may have caused
 the failure.
   We ask that it be sent buck to us and paid half the cal charges
  (about
  $800) insted of the $2660.64 they wanted to repair it. We were just
  going to repalce the ram in try again.
  When we got the meter back it came with befor and afer data Like
  before 10 volts read 9.957 and after it read 10.9 so they did
  something or the meter drifted that much.
  The problem is  0.1 volt and 1.0 volts failed at 8 and 10 MHz but
  passed at
  4 MHz.
  4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1
  volt reads 0.085712 Lower Limit is 0.0959
  2
  0
  FAILED
  10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED
 
  4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt
  reads
  0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower
  Limit is 0.84900 FAILED
 
  The AC after readings are the same. I do not see how AC after could be
  that identical even if they did not try to calibrate it. Did they just
  copy the before data and call it after data?
 
  My best guess is that if the 4 MHz is in and the higher frequencies
  are not the meter requires some

Re: [volt-nuts] HP 3458A repair.

[J. L. Trantham]

John,

Can you give us more information?  Serial number, Rev. number, CALNUM?  How
much to invest will be determined by age and other condition.

It doesn't sound like a simple CALRAM issue but changing the CALRAM is
relatively easy.  I removed all three DALLAS chips in mine and installed
sockets.  The CALRAM can be read with a chip programmer and the data written
to a new DALLAS chip.

I would also call Gary Bierman at the Loveland Cal Lab and have a long talk
with him.  He has a lot of insight into these meters and generally prefers
to do a component level repair rather than an assembly level repair.  The
charge sounds like their standard repair charge, no matter what the problem
is, and includes a 'fresh calibration' along with a warranty, a year I
think, but Gary will be able to answer that question.  

Also, once you get the meter calibrated by Agilent (and thus prove it is
functioning normally) it will be eligible for their 'repair agreement' which
is $178.68 per year.  I would consider buying a 5 year agreement after the
repair.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of John Phillips
Sent: Tuesday, September 17, 2013 3:36 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3458A repair.

Hi,
I have a 3458A that we sent to Agilent for calibration which it failed.
Before we sent it we calibrated it and it looked good to us. The infor. we
revived led us to believe that the cal memory may have caused the failure.
 We ask that it be sent buck to us and paid half the cal charges (about
$800) insted of the $2660.64 they wanted to repair it. We were just going to
repalce the ram in try again.
When we got the meter back it came with befor and afer data Like before 10
volts read 9.957 and after it read 10.9 so they did something or the
meter drifted that much.
The problem is  0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at
4 MHz.
4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 volt
reads 0.085712 Lower Limit is 0.0959
2
0
FAILED
10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED

4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt reads
0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower Limit
is 0.84900 FAILED

The AC after readings are the same. I do not see how AC after could be that
identical even if they did not try to calibrate it. Did they just copy the
before data and call it after data?

My best guess is that if the 4 MHz is in and the higher frequencies are not
the meter requires some kind of mechanical adjustment to get the frequency
response   withing spec or the AC board needs to be repaid.

Are they charging a standard repair charge to do a calibration? I do not see
changing the memory to fix this.

Where would you go from here if this was your meter?


--
John Phillips
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Re: [volt-nuts] Fluke 735C - Information Needed

[J. L. Trantham]

Same color scheme on the batteries in the 5315A.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Chuck Harris
Sent: Tuesday, September 10, 2013 10:30 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 735C - Information Needed

Nope, I was talking about GE and their early Nicads..

And, the cylindrical sealed LEAD acid cells were also originally
commercialized by GE.  They later spun off that division to became GATES.

I had an old SOLA UPS that was made in the mid 1960's that was full of GE
SLA's... The color scheme of the cells was exactly the same as the later
GATES cells.
(Black bottom, white top with red trim...)

and I had an old Sulzer 2.5A double oven oscillator that was full of the GE
Nicads from about 1960.

GE was big in battery research in the late 50's, early 60's.

I don't recall the exact order, but there is a big connection between GE,
Gould, and GATES batteries.

... both Nicads and SLA's.

-Chuck Harris

J. L. Trantham wrote:
 Chuck,

 Do you mean 'commercialize the cylindrical sealed LEAD cells'?  The 
 cylindrical cells in the 6 V battery that powers the HP 5315A is a 
 Gates IIRC.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of Chuck Harris
 Sent: Tuesday, September 10, 2013 9:53 AM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] Fluke 735C - Information Needed

 As I recall, GE was first to commercialize the cylindrical sealed 
 Nicad cells.  They spun off their battery division to Gould, then to 
 GATES... or some such memory muddled permutation like that...

 -Chuck Harris
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Re: [volt-nuts] Fluke 735C - Information Needed

[J. L. Trantham]

Will,

Thanks for the info.  I'll download the 732A manual and see how it compares.

It is quite 'the beast'.  I plugged it in, connected it to my (recently
Fluke calibrated) Fluke 8846A and it read 10.0 VDC.  This AM it read
10.7 VDC

The 'TH' resistance read about 8000 ohms (IIRC) and slowly came down as the
unit 'warmed up'.  This AM it is about 3330 ohms.   I'd love to know what
the 'normal value' of this is at operating temperature.

I need to replace the NiCd's and 'clean up' some corrosion on the battery
charger board but it looks like it will be an interesting addition.

It has a 'sticker' relating calibration in 1982 by 'Primary Standards Lab'
with a 're-cal' date 3 months later.  So, that would fit as a 'transfer
standard'.

I'll have to get it 'back in shape', allow it to stabilize for a couple of
weeks then see what it is on my 3458A.

Do you have any 'specifications' or other documents about it?

Thanks again.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Will
Sent: Saturday, September 07, 2013 7:57 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Fluke 735C - Information Needed

735C = prototype version of the 732A. 10V output only, no 1V divider.

As far as I know it was used for DC transfer experiments from the Fluke
primary lab to their other calibration sites.


2013/9/7, J. L. Trantham jlt...@att.net:
 Does anyone have any information about the Fluke 735C 10.0 DC 
 Voltage Standard?



 Thanks.



 Joe

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[volt-nuts] Fluke 735C - Information Needed

[J. L. Trantham]

Does anyone have any information about the Fluke 735C 10.0 DC Voltage
Standard?

 

Thanks.

 

Joe

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Re: [volt-nuts] Old Weston cells

[J. L. Trantham]

Joe,

Do you have any data about prior measurements of these cells or their
history?

I read somewhere there is a predicted decline rate based on time and
temperature IIRC.

Once you get the meter calibrated, you can 'track' their measurements.

Might also be time for a 'differential voltmeter' to add to the 'stable'.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Monday, August 26, 2013 9:59 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] Old Weston cells

I got my hands on a few very old, unsaturated cells. I figured that they
would be no good after all this time. Just out of curiosity, I measured them
on my 3457A, which hasn't been sent off for calibration yet.

DMM was set to 3 V scale to keep the input impedance high. Room temperature
= 26 C.

Cell #1 = 1.018288
Cell #2 = 1.018236
Cell #3 = 1.018224

I read that when they get below 1.0183 V, they are no good. Is there any
(easy) way to rejuvenate these cells?

Joe Gray
W5JG
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Re: [volt-nuts] HP 3457A calibration?

[J. L. Trantham]

I would agree, the point of keeping the cal data intact is the ability to
tell if the unit is 'in tolerance' on arrival at Agilent, useful information
about the 'quality/stability' of the meter, I think.

Also, the 'cal number' is stored in the 'cal RAM'.  If you send the 3457A in
with no cal data stored and it comes back with a 'cal number' of '1', I
guess you also get the answer to the question of how the 'cal number'
increments after a visit to Agilent.

Is there a 'cal number' stored in other 34xxA DMM's?  3478A for instance?

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Dr. David Kirkby
Sent: Tuesday, August 20, 2013 12:39 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3457A calibration?

On 20 August 2013 02:59, J. L. Trantham jlt...@att.net wrote:
 Interesting video.

A bit of a silly video IMHO. I can't take anyone seriously who measures the
noise on a 6.5 digit multimeter by looking at the digits which change as it
is across his standard bench power supply.
Personally I would have thought one measured the stability of the bench
supply by measuring with the DVM rather than the other way around

 On the 3458A that I was able to 'kill' the 'cal RAM', the 'cal 
 counter' was at '1' when I received it.  When I finished doing my 'home
cal' on a 'blank'
 'cal RAM', the 'cal counter' was about 20 or so.  It appears that 
 every measurement that is calibrated increments the 'cal counter'.

I was thinking about that cal ram, and the issues changing the battery. If
one intends sending the meter away for cal, is there any point in worrying
about if the ram is kept alive? I guess it might be nice to know the
performance before it was calibrated as Agilent will give you, but there is
a bit of a risk of damaging chaning the battery live.

I intend changing the battery in mine then sending it for cal.

Dave
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Re: [volt-nuts] HP 3457A calibration?

[J. L. Trantham]

Joe,

You might start with just measuring the battery voltage.

There are two different batteries used in the 3457A, one that is obsolete
and the other still obtainable.  Per the manual, there are two resistors
that need to be changed if switching from the 'obsolete' battery to the 'new
battery'.  However, I wonder if the resistors even need to be changed.

See message #48954 in the archives and the several messages surrounding
that.

If the battery is 'OK', I would favor just sending it to Agilent for
calibration, unless you can 'SAFELY' change the battery while preserving the
cal data.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Monday, August 19, 2013 10:16 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP 3457A calibration?

Someone pointed out in the comments that his DMM was probably calibrated
once or twice at the most.

From looking at what is on this guys shelf, he has way more money than I do
to spend on test equipment. I'm jealous :-)

Speaking of too much test equipment, that guy Dave who does the EEVBlog
videos also has a lab to drool over. I don't know what he does for a living,
but he seems to be more knowledgeable than the guy from South Africa (who is
also long winded and boring).

As for the cheaper solution, I just bought a 3457A. I expect to see it
this week. After checking it out for a bit, I'll be sending it to Agilent.
Although it may seem ridiculous to spend $200 getting it calibrated, I
figure that I'd be better off having Agilent do it this time, so I know
where I stand.

I'll have to read the cal counter before and after sending it to Agilent.
I'll let you know the results.

If the battery looks original, I'll have to change that out before sending
it for calibration. I know that I have to keep the SRAM powered, so I don't
loose the data already there.

Joe Gray
W5JG



On Mon, Aug 19, 2013 at 7:59 PM, J. L. Trantham jlt...@att.net wrote:

 Interesting video.

 His 'cal certificate' shows no data other than 'in tolerance' and the 
 'standards' used to established that.

 He also makes a point of the 'calibration counter'.

 On the 3458A that I was able to 'kill' the 'cal RAM', the 'cal 
 counter' was at '1' when I received it.  When I finished doing my 
 'home cal' on a 'blank'
 'cal RAM', the 'cal counter' was about 20 or so.  It appears that 
 every measurement that is calibrated increments the 'cal counter'.

 I don't recall how many ranges the 3457A has but add them all up and 
 that is what I would expect the 'cal counter' to increment by once you 
 finish a 'home cal'.

 Since Agilent does all this via HPIB (at least that's what I think), 
 it increments the 'cal counter' only by '1' step.

 I would opt for a 'cheaper' 'seems to be working' 3457A then send it 
 to Agilent for their calibration rather than spend extra for someone 
 else's calibration.

 Joe
 WB4BPP

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of Joseph Gray
 Sent: Monday, August 19, 2013 8:20 PM
 To: Discussion of precise voltage measurement
 Subject: [volt-nuts] HP 3457A calibration?

 Recently, we were discussing where to get a DMM calibrated. Someone 
 mentioned an ebay seller in Albuquerque who had their meters 
 calibrated across town by a company with a similar name.

 I am currently watching a YouTube video about the HP 3457A. At around 
 7 minutes, take a look at the calibration certificate when he holds it up.

 http://www.youtube.com/watch?v=HfxpJCdgVwc

 Joe Gray
 W5JG
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Re: [volt-nuts] DMM calibration

[J. L. Trantham]

Joe,

Sorry to be so late answering this post but I'm 'tied up' right now and
can't get to all my data.

However, I have sent DMM's to Agilent (3458A), Fluke (289 and 8846A), and
Ametek - Solartron (7081).

Agilent was for their 'Agilent Cal' and it included 'As Found' and 'As Left'
data with 'adjustments' made for meters that were 'in cal' 'As Found'.

Fluke was for their Z540 cal.  On the 289, three types of data were offered,
'As Found', 'As Left', and 'As Found - As Left'.  Both my 289's were 'in
cal' and all I got back was 'As Found - As Left' and no adjustments were
made.  I can't recall what the 8846A was but I think it was for their Z540
cal, some measurements were out of cal, and adjustments were made.

Ametek gave 'As Found', 'As Left', and both repairs and adjustments were
made and included returning the replaced parts.

Comparing these meters to each other, using a Fluke 335A, Fluke 5450A, EDC
CR103J, and a Fluke 5100B, they are amazingly close.  Therefore, I feel that
these three companies provide a good service.

I had occasion (as a result of 'killing' the NVRAM by trying to read it
while still 'hot' from the removal process) to calibrate a 3458A using my
recently calibrated 7081.  I did not have a satisfactory AC source at the
time and used a 3326A, Fluke 335A, and some standard resistors.  I then sent
the 3458A to Agilent and the 'As Found' data was all 'in cal' except for two
of the 'mid-range' AC scales.

Now that I have a Fluke 5100B, I think I could do a good job calibrating any
meter by using my 3458A as a 'transfer standard'.

I have also calibrated a 3478A that I managed to lose the NVRAM data on and
it appears to be accurate as well.  I have not sent it to Agilent though I
have been thinking about doing that.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Wednesday, August 07, 2013 11:30 AM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] DMM calibration

I just got the following quote for getting my HP 3478A calibrated.

35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.

I still didn't get any explaination as to exactly what the lab does for each
of these price points. When I asked about the Level 4 listed next to the
meter, I was told that it is the difficulty level. Still not telling me
much. I have read the procedure in the HP service manual and it is very
easy. You set some volt, amp, ohm values on the standard, then push some
buttons on the meter.

I understand about getting data or not, it is the other aspects that I don't
understand. What is Z540, 17025 and logo calibration?


Joe Gray
W5JG
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Re: [volt-nuts] HP 3457A

[J. L. Trantham]

Joe,

I looked at the listing you posted. The unit looks very nice.  However, the
units are selling in the $150 -  $250 range, although I note some of the
units you linked to have sold for the price asked.

There has been considerable discussion on the list about the 3457A and some
differences between units, depending on serial number, having to do with the
circuitry about the backup battery for the RAM.  I would recommend you
search the archives about that.  Also, there are various options for the
rear compartment that may or may not be useful so being able to see the back
of the unit to see what is installed and what the serial number is would be
useful.

I prefer to use the original manufacturer's calibration services when it
comes to Agilent or Fluke just to be able to eliminate the 'trust
uncertainty' with 'outside labs', since I have little experience in using
various calibration labs.

Therefore, my choice would be to look for a desirable 'used' unit then clean
it up myself, check the date on the backup battery and possibly change it
(with the need to keep voltage applied to the unit while unsoldering the
battery lest losing the CAL data - careful there - 'Danger, Danger, Will
Robinson') then send it to Agilent for calibration ($204.22 for the Agilent
Calibration).

If you are looking for a currently supported unit, I would consider the
Fluke 8846A.  Can be had for under $1000.  A bit more expensive but
currently available and currently supported.

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Saturday, August 10, 2013 9:20 PM
To: Discussion of precise voltage measurement
Subject: [volt-nuts] HP 3457A

If I want to buy a used 3457A, is it better to buy one as-is and send it
for calibration, or perhaps spend a bit more and get one already calibrated?
Just one example:

http://www.ebay.com/itm/HP-3457A-6-5-Digit-Lab-Quality-Front-Terms-Fully-Ref
urbished-NIST-Cal-/300928374155

Joe Gray
W5JG
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Re: [volt-nuts] EDC VS330 Voltage Standard

[J. L. Trantham]

Sorry to hear that.  I suspect someone has one somewhere.  Hopefully you'll
get lucky as well.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Monday, August 05, 2013 1:17 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] EDC VS330 Voltage Standard

Just a follow up. You were lucky getting a manual. I just got a reply from
Krohn-Hite, saying that no manual was avaialble.

Joe Gray
W5JG



On Sun, Jul 28, 2013 at 4:11 PM, J. L. Trantham jlt...@att.net wrote:


 Do you have a manual?  I have an EDC CR103 voltage and current 
 standard and was able to find a 'partial' manual on the web.  It noted 
 that a complete manual was available from Krohn-Hite and to contact 
 them at (508) 508-1660 or sa...@krohn-hite.com to purchase a complete 
 manual.  When I emailed them about obtaining one, I received a 
 complete .PDF manual by return email from one of their service 
 engineers.  Others have had a similar experience.
  When
 asked, Krohn-Hite asked that the manuals not be 'shared'.  So, if you 
 can't find one, you might try contacting them.

 Good luck.

 Joe

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Re: [volt-nuts] EDC VS330 Voltage Standard

[J. L. Trantham]

Same issue as with the time-nuts and the man with one watch versus more.  No
way to tell except to 'vote with the majority'.

So, the answer is 'probably'.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Joseph Gray
Sent: Sunday, July 28, 2013 6:37 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] EDC VS330 Voltage Standard

When I get the VS330, I think I'll first try setting it for 5 V and
comparing the 3478A reading with what I got with the MAX6350. If I get about
the same reading of 5.0026 V, is it safe to assume that the 3478A is in
error?


Joe Gray
W5JG



On Sun, Jul 28, 2013 at 5:02 PM, Joseph Gray jg...@zianet.com wrote:

 Thanks for the subject. Actually, I had intended to put that exact 
 subject on it, but forgot and clicked send.

 I couldn't find even a partial manual for the VS330, but the 1030A 
 partial manual looks like it would be very similar. Would you please 
 send me the email contact at K-H that sent you the manual?

 Joe Gray
 W5JG



 On Sun, Jul 28, 2013 at 4:11 PM, J. L. Trantham jlt...@att.net wrote:

 Joe,

 Pardon my adding a 'subject' to the thread.

 If all you want is a 'house standard', you're probably 'in the ball
park'.
 If you want to set up a home 'metrology lab' (careful, this 'metrology'
 stuff can be as addicting as the 'time' stuff), you should get 
 something calibrated by an outside lab.  I would send the highest 
 resolution meter out for cal.  I don't know if calibration services 
 are available for the VS330.

 If the 3478A is it, I would vote to send the 3478A to Agilent for 
 their 'Agilent' cal ($204.22 per their website) and see where you 
 are.  The meters I have sent to Agilent for their 'Agilent' cal, come 
 back with 'as found'
 and 'as left' values and is very informative about the capabilities 
 of the meters.  The meters I have returned for a repeat 'Agilent' cal 
 have all returned with their 'as found' values still in cal.

 Once you get the 3478A back, you will have a number of 'calibrated'
 measurement capabilities.

 Do you have a manual?  I have an EDC CR103 voltage and current 
 standard and was able to find a 'partial' manual on the web.  It 
 noted that a complete manual was available from Krohn-Hite and to 
 contact them at (508)
 508-1660
 or sa...@krohn-hite.com to purchase a complete manual.  When I 
 emailed them about obtaining one, I received a complete .PDF manual 
 by return email from one of their service engineers.  Others have had 
 a similar experience.
  When
 asked, Krohn-Hite asked that the manuals not be 'shared'.  So, if you 
 can't find one, you might try contacting them.

 Good luck.

 Joe



 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 
 On Behalf Of Joseph Gray
 Sent: Sunday, July 28, 2013 4:06 PM
 To: volt-nuts@febo.com
 Subject: [volt-nuts] (no subject)

 I just had a friend buy this for me (I don't have an ebay account). I 
 hope I didn't make a mistake.


 http://www.ebay.com/itm/Electronic-Development-Corporation-EDC-VS330-
 VOLTAGE

 -STANDARD-/161069656213?nma=truesi=PiGtcBMSdSOxgbm9DhiZ6iLo1GQ%253D
 orig_cv 
 ip=truert=nc_trksid=p2047675.l2557http://www.ebay.com/itm/Electron
 ic-Development-Corporation-EDC-VS330-VOLTAGE-STANDARD-/161069656213?n
 ma=truesi=PiGtcBMSdSOxgbm9DhiZ6iLo1GQ%253Dorig_cvip=truert=nc_trk
 sid=p2047675.l2557

 Of course, once I have it, it's the chicken and egg problem. The best 
 I have to check it against is an HP 3478A that was last calibrated an 
 unknown number of years ago. It has a little round sticker over the 
 CAL switch on the front, but no dated calibration label that I can 
 see. It came from a repair facility that closed a few years ago.

 Actually, the reason I was tempted to buy the VS330 was because I 
 think the 3478A is off a bit. A while back, I built a simple 5V 
 reference with a MAX6350. The 3478A read high. I took the reference 
 to work and the best Fluke handheld we have was dead on (I don't 
 remember the model right now).

 I made the measurement again last night and the 3478A reads 5.0026 V, 
 with the last digit fluctuating. Room temperature was 26 C.

 I guess obsessing about these things has brought me here to the Volt
Nuts.
 I have been on Time Nuts for several years.

 Joe Gray
 W5JG
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Re: [volt-nuts] Solartron Files

[J. L. Trantham]

I probably have it.  Can you give me the specifics of what you are looking
for?

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Sam Reaves
Sent: Friday, May 10, 2013 7:46 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] Solartron Files

Hello,

Does anyone have the two Solartrin 7081 files posted by Mickle?

The source I found has corrupt files.

Thank you,

Sam
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Re: [volt-nuts] Solartron 7071 beeping about twice a second

[J. L. Trantham]

Dave,

My knowledge of 'FOD' comes from the Navy, in particular, aircraft carriers.
It is an acronym standing for 'Foreign Object Damage' or 'Foreign Object
Debris'.

On an aircraft carrier, there are periodic 'FOD patrols' whereby the crew
walk the flight deck, shoulder to shoulder, stern to bow and bow to stern,
to identify and remove any object that might get 'sucked up' into the intake
of a jet engine as aircraft are being launched.  A particularly bad time for
an engine failure and usually costs an aircraft and not uncommonly a crew.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of David C. Partridge
Sent: Thursday, January 31, 2013 3:24 AM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7071 beeping about twice a second

 I presume that when you push the 'DIG-FILT' key, pin 5 and 6 are 'shorted'
 when measured on the key board connector.

Correct. 

 'FOD'

OK, I'll bite, what does that one mean?

 try to open the keyboard

I'm pretty sure the keyboard isn't amenable to being opened without
permanent damage.

Dave

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Re: [volt-nuts] Solartron 7071 beeping about twice a second

[J. L. Trantham]

One other thing.

I presume that when you push the 'DIG-FILT' key, pin 5 and 6 are 'shorted'
when measured on the key board connector.  I think this is what you are
saying but just want to make sure.  If so, then I would conclude that there
is a piece of conductive 'FOD' loose in the keyboard or the key was stuck.
You might want to connect your 'beeping' DMM to indicate a short to pins 5
and 6 from the keyboard then shake the keyboard to see if it will 'beep'
when you get it in the proper position.  If an occasional beep occurs, then
I would try to open the keyboard and clean the connectors.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of J. L. Trantham
Sent: Wednesday, January 30, 2013 1:50 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7071 beeping about twice a second

I wonder if you have a small piece of 'FOD' floating around in the front
panel contacts?

I have never taken a front panel for one of these apart but would suspect
there would be a way to separate the buttons from their contacts and perhaps
clean them.  If you could do the disassembly in a clean plastic tub then
carefully inspect for any small 'pieces' that might fall out, it might
explain what the problem was.

Glad you are making progress.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of David C. Partridge
Sent: Wednesday, January 30, 2013 12:53 PM
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7071 beeping about twice a second

And just to make a monkeys uncle out me, it just started working after
reconnecting the keyboard for the nth time.

Confused ... You bet, especially as I cannot now provoke the fault (except
by holding down the DIG-FILT key or shorting pins 5 and 6).

Dave
-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of David C. Partridge
Sent: 30 January 2013 17:49
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7071 beeping about twice a second

Further information:

Shorting pins 5 and 6 of PL2 causes the same symptoms, as does pressing and
holding the DIG FILT key on another meter.

The odd thing is though that an ohms test between 5 and 6 of keyboard is OC
- which does not make sense to me?

Dave

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Re: [volt-nuts] 7081 AC buffer *again*

[J. L. Trantham]

Is it possible that it is, somehow, 'picking up interference' from your
'house standard'?  How close to 10.000 000 000 MHz is it?

100 mV P-P is fairly substantial.  Otherwise, is it oscillating?

Good luck.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of David C. Partridge
Sent: Tuesday, January 29, 2013 9:54 AM
To: 'Discussion of precise voltage measurement'
Subject: [volt-nuts] 7081 AC buffer *again*

I've returned to the 7081 that was giving me troubles in the AC buffer
circuit.

Probing the output test point (TP 705) I'm seeing about 100mV pp (approx) at
about 10MHz.  This would likely explain the strange results I was getting
last year.  However I'm puzzled as to where it can be coming from!!!  Any
suggestions gratefully received.

Regards,
David Partridge

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Re: [volt-nuts] solartron 7081 rom reading q

[J. L. Trantham]

MK,

I am not aware of a way to read the EPROM's without removing them.  Dave
Partridge has done a lot of work on these along with Mickle, both on the
list.

Dave Partridge's EPROM images are on Didier's site.  I have read the EPROM's
from two of these units, of two different vintages IIRC, and can send them
to you if you need them.  I used the images from one to upgrade the other to
the latest version that I/we know of.

I know that there is an undocumented command for the HP 3458A that allows
you to read the memory but I don't know if the same sort of 'global' access
exists on the 7081.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of m k
Sent: Saturday, January 12, 2013 2:40 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] solartron 7081 rom reading q







Hi,

Finally able to talk to the meter through RS232.
Is there any way to dump the rom contents using the RS232? or do the chips
have to be put in a reader to get the values out?

MK

  
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Re: [volt-nuts] Fluke 335A versus HP 740B

[J. L. Trantham]

I am not familiar with the HP 740B.  It looks like it needs a special
connector for the front panel to get an output or input.  If true, I would
score that as a negative.

I have a 335A that had some problems when I got it.  Turned out it was just
some dead electrolytic caps that were identifiable by sight, bulging, etc.
I replaced them and all was well.  The manual is readily available.  It uses
binding posts for connection.  It recently developed a new problem, the
'Overload' light is continuously illuminated though the output is still
there and accurate.  I suspect a transistor issue but have not had a chance
to explore yet.

You will need a 5 1/2 digit DMM, minimum, to be able to see the 1 uV change.
Measuring that is a bit of a challenge in that it is not stable, voltage
source, meter, temp changes, etc., all playing a role.  However, I seem to
recall you have a Solartron 7081 so you can watch the 1 uV all the way up to
10 V.

I have been looking for an affordable 335D but, so far, have not found one.
However, I found a Fluke 5440B/AF.  It just arrived recently, seems to work
on initial, superficial, check out, but I have not had a chance to
incorporate it into my rack yet or investigate it's stability.  

However, at the current price, why not get all three, 335A, 335D, and 740B?

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of David C. Partridge
Sent: Friday, December 14, 2012 8:16 PM
To: 'Discussion of precise voltage measurement'
Subject: [volt-nuts] Fluke 335A versus HP 740B

Both DC Voltage standards up to 1000V or so, and also null differential
meters.

Also both being sold by the same vendor as the other stuff

Do the assembled mavens have a view as to which is preferable?

Thanks
Dave


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[volt-nuts] (New to me) 3458A Trivia

[J. L. Trantham]

I just added a 'new' (manufacture date late 1998) 3458A to the collection
that had Option 001 and 002 noted on the rear panel.  When it arrived, all
seemed well, passed self test, seemed accurate but with OPT? and ENTER, it
returned OPT 1,0 which implies OPT 001 is installed.  However, I thought
that it did not have OPT 002 installed.

I called Agilent, spoke with Gary Biermann, and learned that there never was
a way to tell from the front panel if OPT 002 is installed or not.  The only
way to tell is to open it up and look at the part number on the DC Reference
Board.  

I did this and discovered that it, indeed, had part number 03458-66519
installed, the 4 ppm reference.  03458-66509 is the 8 ppm reference and
03458-66529 is the 'ultra high stability' 2 ppm reference.

Thought I would share this 'pearl' but I suspect most know this already.
Was news to me though.

Joe



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[volt-nuts] Traveling Standard

[J. L. Trantham]

Anyone heard from Bob Smither lately?  I emailed him direct but have had no
response.

Thanks.

Joe


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Re: [volt-nuts] HP3457 - Cal Key for Solartron 7061

[J. L. Trantham]

Can't recall if I posted this here or not but the Cal Key for my 7081 also
fits the 7061.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Fabio Eboli
Sent: Wednesday, August 22, 2012 2:58 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] HP3457



As for the key, I can duplicate mine and send it to you,
if you want to try another key.

Fabio.



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Re: [volt-nuts] HP3457

[J. L. Trantham]

Fred,

700 euro seems a bit high, at least by US standards, for a 3457A.  It is a
good meter and I have one.  Though no longer supported, Agilent will still
calibrate one for $200.22, according to their website.

You might want to consider a Fluke 8846A.  I  have seen them sell for $900
new.  I don't have one but it was going to be my next addition until I got a
3458A.

What is the issue with the 7061?

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Fred Schneider
Sent: Tuesday, August 21, 2012 2:00 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] HP3457

I have a solatron 7061 but i am not very impressed with it. Must I go
looking for an alternative or is this 7061 when i gave it a good checkup /
overhaul a good meter ?
I am offered a 3457 for 700 euro and the owner, will calibrate it (he has
several calibrtors, standards and a couple of 3458  meters. My intuition
tells me to trusts him ( and that had never let me down before)) 

But he also told it is only 7,5 digit over hpib, and has 6,5 digit display.

My Keithly 2000 is 6,5 digits and over RS232 i get two digits extra. I once
tried that, but that took me a lot of time to get it more ore less working,
I am not so into computers and afraid I do not get it to work.

Is it really better as my ( one year old 2000 ?) and better as my Solartron
can be ?
I am afraid a 3458 is outside my budget.

Fred



Fred PA4TIM
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[volt-nuts] Suggestions for Calibrators or Calibration Standards

[J. L. Trantham]

I am considering adding some 'standards' to my shop.  I am interested in the
ability to calibrate DMM's, using my Agilent Calibrated 3458A as a 'transfer
standard'.

I have a Fluke 731B 10 VDC standard, a Fluke 335A DC Voltage Standard that
goes to 1000 VDC, and some selected standard resistors from 0.1 ohm to 10
KOhm in decade steps.

I also have an EDC CR103 DC Voltage and Current Standard that goes to
11.0 VDC and 111.1110 mA.

In order to complete this 'lab', I would need an AC Voltage Standard and an
AC Current Standard.

What suggestions would there be to address this?

I have thought about a Fluke 5100B as well as a 5450A Resistance Standard,
and 5400A AC Voltage Standard.

If I use my 3458A as the 'transfer standard', I can use it to provide the
additional 'digits' beyond the 5100B.

I also have some LCR meters but I don't have any capacitance or inductance
standards.

Once I have this sorted out, I could 'off load' my earlier, redundant,
equipment.

I would appreciate any and all thoughts about what to add to my 'lab'.

Thanks in advance.

Joe



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Re: [volt-nuts] 7061 On Board Clock and Battery

[J. L. Trantham]

Fabio,

I uploaded the EPROM contents from my meter to Didier's site as well.  The
Floating board I have has 'AA' version firmware while yours is 'CA'.  Mine
uses TMS2516 chips that are 24 pin and I think yours are 2764 28 pin chips.

I'll investigate the statistics function after I make sure it is 'in range'
as far as the calibration goes.

I don't understand 'SP1 and SP2 on floating board are both open circuit'.
To what does this refer?

Thanks.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Fabio Eboli
Sent: Monday, June 25, 2012 10:54 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 7061 On Board Clock and Battery

Interesting, these roms are mine's:
http://www.ko4bb.com/Manuals/04)_ROM_Images_and_Drivers/Solartron_7061_ROMs.
zip

I have also a problem with statistics,
seem that the standard deviation calculation is
wrong:
http://www.febo.com/pipermail/volt-nuts/2012-April/001793.html
If you have time to test yours for this I would be grateful.

Another thing is that on mine SP1 and SP2 on floating board are both
open circuit.

Fabio.

J. L. Trantham jlt...@att.net ha scritto:

 Fabio,

 Thanks for the link to the pictures.  I never seem to remember eevblog
when
 it comes to looking for stuff.

 Your pictures show that your Earthy board is completely different from
mine
 in the area of 'B101'.  You have no place for B101.  Also, your Floating
 board is different in that you have the 'CA' firmware and 28 pin EPROM's.
I
 wonder if anyone has modified my 'version' of the Floating board to use 28
 pin EPROM's and if there would be any utility to doing this.

 I did not get a message directly from you (that I recognized at least).
 I'll try to send you one directly to make sure we can 'establish
 communications'.

 Joe

 -Original Message-
 From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
 Behalf Of Fabio Eboli
 Sent: Monday, June 25, 2012 5:14 AM
 To: Discussion of precise voltage measurement
 Subject: Re: [volt-nuts] 7061 On Board Clock and Battery


 Here are some pics of the mine, only one battery:

http://www.eevblog.com/forum/product-reviews-photos-and-discussion/solartron
 -7061-help-and-come-photos/msg93650/#msg93650

 As for the manual I did try to contact you directly,
 did you read the message?

 Fabio.

 J. L. Trantham jlt...@att.net ha scritto:

 My 7061 has a single battery installed, B501, a 3.6 V Ni-MH
 Rechargeable 3 pin battery.  My 7081 has two batteries installed, the
 same 3.6 V Ni-MH Rechargeable battery and a ½ AA Lithium Battery that
 serves as the onboard clock backup battery.  It is connected with its
 negative pin to a 47K resistor to ground and its positive pin to a
 diode that feeds a connection that is also fed by another diode from
 the main power supply.  The common connection of these diodes feed the
 clock chip.



 On my 7061 there is a location, B101 that appears to be for the same
 type ½ AA Lithium Battery.  The + pin connects to a diode, in a manner
 similar to that described above, and the – pin connects to a ‘space’
 for a resistor, R117, with the other end of the resistor going to
 ground.  Both the battery, B101, and the resistor, R117, are missing.



 My questions are:



 1.   Does anyone have a 7061 with this battery and resistor installed?
 2.   If so, what is the value of the resistor, R117, and what type is the
 battery?



 It seems that this would be an easy addition to get a live clock
 without the need to restart the clock each time the meter is turned
 on.  Or, perhaps there is a reason why this in not a good idea.



 Thanks in advance.



 Joe

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Re: [volt-nuts] Solartron 7061 Service Manual - Does anyone haveone?

[J. L. Trantham]

Dave,

That is always the first place I look but all I found was the ROM images and
the Operating Manual.  I did not see a Service Manual.  I would love to find
one, assuming one is 'out there' somewhere.

I archived the ROM's in my 7061.  The Earthy Board is the same ROM's as on
Didier's site.  However, my Floating Board uses TI TMS2516's and has version
51AA, 52AA, 53AA, and 54AA firmware.  I can send it to anyone that wants it
and can upload it to Didier's site if useful.

My Floating Board has 24 pin sockets for the TMS2516's but room for a 28 pin
socket and 'pads' to solder to tell it if it is using the '16's' that mine
uses or the '64's' that are used for the 'CA' firmware.  I don't know if
there is any advantage to changing this to use the 'later' firmware.

I would appreciate any info on this that anyone has.

Thanks.

Joe

-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Dave M
Sent: Sunday, June 24, 2012 8:08 AM
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Solartron 7061 Service Manual - Does anyone
haveone?

 Date: Sat, 23 Jun 2012 11:12:59 -0500
 From: J. L. Trantham jlt...@att.net

 I am looking for a service manual for the Solartron 7061, paper or
 .PDF. Does anyone know where I might find one?

 Thanks in advance.

 Joe

 *

Joe,
Didier has PDF copies of the User manual, Service manual and ROM images on 
his manual web site at http://www.ko4bb.com/manuals/index.php.  Just search 
for 7061.

Dave M
A woman has the last word in any argument. Anything a man says after
that is the beginning of a new argument. 



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[volt-nuts] 7061 On Board Clock and Battery

[J. L. Trantham]

My 7061 has a single battery installed, B501, a 3.6 V Ni-MH Rechargeable 3
pin battery.  My 7081 has two batteries installed, the same 3.6 V Ni-MH
Rechargeable battery and a ½ AA Lithium Battery that serves as the onboard
clock backup battery.  It is connected with its negative pin to a 47K
resistor to ground and its positive pin to a diode that feeds a connection
that is also fed by another diode from the main power supply.  The common
connection of these diodes feed the clock chip.

 

On my 7061 there is a location, B101 that appears to be for the same type ½
AA Lithium Battery.  The + pin connects to a diode, in a manner similar to
that described above, and the – pin connects to a ‘space’ for a resistor,
R117, with the other end of the resistor going to ground.  Both the battery,
B101, and the resistor, R117, are missing.

 

My questions are:

 

1.  Does anyone have a 7061 with this battery and resistor installed?
2.  If so, what is the value of the resistor, R117, and what type is the
battery?

 

It seems that this would be an easy addition to get a live clock without the
need to restart the clock each time the meter is turned on.  Or, perhaps
there is a reason why this in not a good idea.

 

Thanks in advance.

 

Joe

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[volt-nuts] Solartron 7061 Cal Key

[J. L. Trantham]

The Cal Key I received for my 7081 also works for the 7061.

 

If anyone needs one, let me know.

 

Joe

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Re: [volt-nuts] Calibration Sources for Solartron 7081

[J. L. Trantham]

Jean-Louis,

My DC standards are a Fluke 731B and Fluke 335A DC Voltage Standards and an
EDC CR103 DC Current and Voltage Standard.

My resistance standards consist of a collection of Leeds and Northrup type
standard resistors as well as a collection of General Radio Decade
Resistance boxes that will get me up into the MegOhm range.

However, AC promises to be a problem.  I guess I will try using a signal
generator and an amplifier to see what output level and stability I can
achieve.

But still, what frequency?  60 Hz?  1 kHz?

Thanks,

Joe


-Original Message-
From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On
Behalf Of Jean-Louis Noel
Sent: Friday, June 22, 2012 3:58 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Calibration Sources for Solartron 7081


Hi J. L.

From: J. L. Trantham jlt...@att.net

 What source could/should I use for the ACV and what frequency for the 
 ACV? I can come up with a power transformer and a variac for 60 Hz.

The stability is not high enough to be useful!
Have a look to http://www.on4jln.be/infos/getfile?file=515A-OM.pdf,
it is the Fluke 515A, to learn how they dealt with that problem. If your 10V
is good you will get better results too. And it needs to be very good to
calibrate the 7081! Stability is more important than everything else and
that is the problem.

Have a good day.

Bye,
Jean-Louis

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[volt-nuts] Calibration Sources for Solartron 7081

[J. L. Trantham]

I recently added another Solartron 7081 to my collection that seems to be
working correctly, is stable and I have upgraded it to the latest firmware.
However, it is clearly not accurate, at least on the 10 VDC scale, measuring
my 10.000 000 standard at about 10.000 840 V while my other meters are +/-
about 10 uV of 10.000 000 VDC.

 

If I understand the calibration procedure correctly, I will need an input
short, an input open, and 'standards' for each of the VDC, VAC, and Ohms
ranges to perform a complete calibration procedure.  This would appear to be
a source for 0.1, 1, 10, 100, and 1000 VDC and VAC along with 0.1, 1, 10,
100, and 1000 kOhm and 10 and 1000 MOhm resistor standards.  I can come up
with the VDC standards and the resistance standards except the 1000 MOhm.  I
don't have 'standards' but I have references that are stable and calibrated
meters (another 7081 and two 3458A's) that I can use to measure my
references and then input their measurements into the DUT 7081 to perform
the calibrations.

 

My questions are:

 

What source could/should I use for the ACV and what frequency for the ACV?
I can come up with a power transformer and a variac for 60 Hz.  I also have
a selection of signal generators and synthesizers for amplitudes up to about
+10 dBm at pretty much any frequency you prefer.

 

What would be the lowest ACV that I could/should use for the 1000 VAC scale?

 

What suggestions for the 1000 MOhm standard?  What is the lowest value that
I could/should use for the 1000 MOhm scale?

 

My plan is to test each scale against my other meters and calibrate only the
scales that are 'out of bounds'.  Good idea or bad?

 

Thanks in advance.

 

Joe

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