Ludger.Lenzen | 7 Feb 20:33 2016
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Fw: Just uploaded to KO4BB: Datron 1281 User Manual & Service Manual

volt-nuts@...

> Gesendet: Sonntag, 07. Februar 2016 um 19:52 Uhr
> Von: Ludger.Lenzen@...
> An: volt-nuts <volt-nuts-bounces@...>, "VOLT NUTS" <volt-nuts@...>
> Betreff: Just uploaded to KO4BB: Datron 1281 User Manual & Service Manual
>
> Hi folks,
> 
> as the owner of the Datron manuals copyright has stopped the business and has given all docs and rigths to
the "Internet Archive", I am now free to upload some documents to Didier great site (KO4BB).
> I uploaded 3 files:
> 1. an optimzed/better version of user manual (with bookmarks & quick links)
> 2. HQ scan of the complete service manuals Vol1&Vol2 (including drawings & schematics)
> 3. HQ scan of the drawing out of service manual Vol2 (only drawings & schematics)
> Hope it is of interest.
> 
> Remark: it's a lot of data (compession/zipping did just minor reduction thus haven't done it).
> 
> BR
> PeLuLe
> 
Ludger.Lenzen | 7 Feb 20:33 2016
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Fw: Datron 1281 / 1271 secret GPIB cmds for CALRAM-Readout


> Gesendet: Sonntag, 07. Februar 2016 um 18:30 Uhr
> Von: Ludger.Lenzen@...
> An: volt-nuts-bounces@...
> Cc: "Adrian Bernhard" <acbern@...>
> Betreff: Datron 1281 / 1271 secret GPIB cmds for CALRAM-Readout
>
> Hi volt-nuts
> 
> I like to backup the Datron 1281 CAL RAM data. Mine need to be refurbished (caps replacement, case cleaning...)
> The 1281 quite good in cal (~3ppm difference to my 3458A which had last cal 2014/OCT), which I don't want to risk.
> In any case this migh a helful knowledge for all of us.
> 
> I am lucky having another 1281 "for part" without a Display- and DC-Assembly but a wokring Digital Board.
> I dumped the ROM to have a deep look into the GPIB commands and searched for potential undocumented existing
> (like it was done for the 3458A already).
> 
> I found following, in the service and user manual not documented, potential commands (?):
>   RAM = may a RAM command, seems to be the best chance
>   PRIM = may a subfunction of RAM for primary RAM
>   SECN = may a subfunction of RAM for secondary RAM
> 
>   IPZ = no glue yet
> 
>   YEUK = command to set something, no glue yet about function
>   YEUK? = query comand of the YEUK command
> 
>   CALISS? = seems to be a qery for calibration purpose
> 
> To (hopefully) save some of the allways limited private time, I would like to aks, if some of you have seen
(Continue reading)

Mark Sims | 3 Feb 05:10 2016
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Oldaker is no more...

I stopped by my favorite electronics store to buy some more Oldaker meter probes.   Alas,  I was told that
Oldaker had a fire and is no longer in business.   They were a small (7 person), family owned business that
made really nice and affordable test leads.   Apparently they don't plan on restarting the business.
I've used their leads/probes for years and have never had one fail.  And the tips are damn sharp... 		 	   		  
new | 31 Jan 20:49 2016

Re: volt-nuts Digest, Vol 77, Issue 15

I'm thinking of doing non-commercial 'calibrations' for
folks like us volt-nuts.

  Since I have three 3458s, three 732As, a 732b, a 4214,
an sr104, a 4210, all NIST cal'ed and I could do front-panel
adjustments for the 3457.

  Would anyone here like to do that? I would start by
replacing the cal battery, too.

   I could give the 'as found' and 'as left' numbers too,
for the meters that arrived with 'alive' batteries.

  Probably best to do it on fleabay to protect everyone
involved.

  If this post is a violation of volt-nuts policy, please take it down!

Willy

On 1/31/2016 12:00 PM, volt-nuts-request@... wrote:
> Send volt-nuts mailing list submissions to
> 	volt-nuts@...
>
> To subscribe or unsubscribe via the World Wide Web, visit
> 	https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> or, via email, send a message with subject or body 'help' to
> 	volt-nuts-request@...
>
> You can reach the person managing the list at
(Continue reading)

Four Designs Company | 31 Jan 18:42 2016
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Re: 3457A - should I preserve SRAM contents, or purposely, corrupt them by removing power?, (Dr. David Kirkby (Kirkby Microwave Ltd))

A question to ask Keysight, if the instrument arrives without cal 
constants, will they consider that a "repair", or a calibration? Very 
different prices. I suspect that Keysight, and any other cal lab that 
has MetCal, will hook it up to a multifunction calibrator, computer and 
let it run.

If you jumper another battery with current limiting across the existing 
during replacement to preserve the cal, you could then ask for before 
and after data from the cal lab. This is typically an extra cost item.

I work on DMM's frequently, if this were in my shop, I would first make 
sure that the instrument is stable, regardless of the absolute accuracy, 
and that the relays  have not become noisy. This can be checked by 
rapping them lightly with something like a screwdriver handle .
Also a good opportunity to check and replace any electrolytic caps that 
have poor ESR.

I was just working on a pair of Data Precision meters, and both had 
noisy, unstable relays. This is a frequent problem, even with the 
"sealed" relays such as found in the HP. I would also make sure that any 
Front/Rear input switching is noise free, as these are often unused for 
years, if ever, and can cause problems.

Bob

On 1/31/2016 9:00 AM, volt-nuts-request@... wrote:
> Re: 3457A - should I preserve SRAM contents, or purposely
>        corrupt them by removing power?
>        (Dr. David Kirkby (Kirkby Microwave Ltd))

(Continue reading)

Re: Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

I use these

https://www.conrad.nl/nl/eve-12-aa-axial-er14250-speciale-batterij-12-aa-axiaal-soldeerpin-lithium-36-v-1200-mah-1-stuks-650772.html

Met vriendelijke groeten
Regards
Frans

info@...
http://ElectronicsAndBooks.com
WEB ElectronicsAndBooks DOT com
TEL +31-(0)6-20577501
Netherlands

Discere ne cesses

--------------------------------------------
On Sun, 1/24/16, Dr. David Kirkby (Kirkby Microwave Ltd)
<drkirkby@...> wrote:

 Subject: Re: [volt-nuts] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter
 To: "Discussion of precise voltage measurement" <volt-nuts@...>
 Cc: "hp_agilent_equipment@..." <hp_agilent_equipment@...>
 Date: Sunday, January 24, 2016, 11:08 PM

 On 24 January 2016 at
 21:24, Poul-Henning Kamp <phk@...>
 wrote:

 > --------
(Continue reading)

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3457A - should I preserve SRAM contents, or purposely corrupt them by removing power?

As noted in another thread, I want to replace a battery in a 3457A that has
not been replaced in at least 11 years. The instrument has not been
calibrated in that time either. At the time it was purchased from a dealer,
I was told it was within specification, but if I wanted it calibrated I
would need to pay. I never did have it calibrated, so have no historical
data about this. I've no idea when it was calibrated, and have no cal
certificate, so have no idea of the errors at the time of calibration.

I now want to change the battery, *and* send it to Keysight for calibration
- I have a healthy skepticism of 3rd party labs, so would rather pay more
and get the job done by Keysight.

I'm wondering if I would be better purposely removing the battery, and
putting a short across the SRAM so I ensure the contents are definitely
lost. My logic is that

1) If I send it to Keysight and the cal data is corrupt, they will set the
meter correct.

2) If sent to Keysight, with the cal data in tact, then if its within
specification they will not adjust it. So if the limit on some parameter is
1%, and the error is 0.5%, then it will not be adjusted. But if the SRAM is
corrupted, the error will be huge (if it will read at all), so it would
force Keysight to adjust it to the correct value. At that point the error
should be effectively zero given its a 6.5 digit multimeter, which means
the uncertainly in Keysight's measurements should be much lower than the
uncertainty of my meter.  So by corrupting the SRAM, I should get a meter
returned to me that is more accurately calibrated than if I take the
trouble to preserve the SRAM contents.

(Continue reading)

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Fall of SRAM voltage in a 3457A without external power

I decided to try a little experiment on my 3457A, When on mains the SRAM
gets 4.8 ~ 5 V. This does not seem to be well regulated, so I assume
depends on mains voltage. Once power is removed, the voltage on the SRAM
stays well above the battery voltage for some considerable time, which I
assume is due to a decoupling capacitor. My 10 M Ohm input Z multimeter is
loading the circuit too much to continuously monitor the voltage, but a few
checks indicated the voltage across the SRAM is falling quite slowly.
Starting at 4.8 V from mains power, after 23 minutes of no mains power, the
voltage on the SRAM was at 3.4V, which is above the battery voltage (3.03
V). and well above the 2.0 V needed to hold the SRAM contents. Assuming the
SRAM takes a constant current one would expect the voltage to fall linearly
with time. If so, it would take 46 minutes to fall to 2.0 V even without
battery power.

ESD and leakage of the human body would probably make screw this up, so I'm
not suggesting replacing the battery that way if you want to preserve the
contents of the SRAM, but there's a fairly good chance the contents would
remain in RAM if one was reasonably quick, especially if you topped the
voltage up from the mains just before removing it from the chassis.

Dr. David Kirkby Ph.D CEng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT,
UK.
Registered in England and Wales, company number 08914892.
http://www.kirkbymicrowave.co.uk/
Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)
Mark Sims | 25 Jan 01:36 2016
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Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

Although I have not done this on a 3457A,  I have done it on other devices:
Take new 3.6V battery.  Solder silicon diode to new battery lead (near the cell) to drop voltage to 3.0ish
volts.  Solder battery / diode to existing battery leads (near the circuit board).  Cut old battery free. 		
	   		  
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Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

I've got a HP 3457A 6.5 digit multimeter - S/N 2703A04579. It's working
fine, but I'm aware the battery must be at least 11 years old, as I first
bought the meter 11 years ago. I suspect its due for a change.  I'm trying
to find a *reputable* source for a replacement. I want to avoid eBay, due
to the number of fakes on there.

Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around

https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964

would suggest the battery was made by Saft and is a Lithium-manganese
dioxide (Li-MnO2). The size appears to be known as 2/3A. One source
suggests a replacment is the Panasonic BR-2/3AE2SP

Mouser's uk site
http://www.mouser.co.uk/
says shipping is restricted, so only available in the USA.

The nearest I've found to anything remotely suitable is actually a 3.6 V
battery

"CROMPTON ETERNACELL  T32/8AA8F  Battery, Single Cell, Lithium Thionyl
Chloride, 2100 mAh, 3.6 V, 2/3A, Axial Leaded, 16.3 mm"

http://uk.farnell.com/crompton-eternacell/t32-8aa8f/battery-lithium-2-3aa-axial-lead/dp/774017

I'd rather not fit a higher voltage battery, although given it provides
power to some 5 V static RAM, I would not expect it to be a problem. That
(Continue reading)

Bob Fleming | 23 Jan 21:04 2016

keeping water out of enclosures


  The only successful low cost solution I have is drain holes and/or heaters.
Nearly every properly secured water proof enclosure will eventually fill with water if installed with
conduit holes anywhere but the bottom and sometimes even then water will get in the box after the conduit
fills with water. 
This experience is from industrial environments. No matter what I do, eventually some idiot opens the
enclosure looking for something unrelated to my equipment and then does not properly secure the cover.
Bob N5TX

Gmane