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EEVblog => EEVblog Specific => Topic started by: EEVblog on February 03, 2014, 11:17:51 pm

Title: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: EEVblog on February 03, 2014, 11:17:51 pm
A quick look at Dave's Advantest R6142 Voltage and Current Source.
Can it be used as a current reference for the uCurrent?
A look at the stability with temperature and time, and absolute calibration of the unit.
Is it an ebay score, or ebay junk?

EEVblog #576 - Advantest R6142 Current Voltage Generator (https://www.youtube.com/watch?v=tSzem8xshxk#ws)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: nathanpc on February 03, 2014, 11:40:56 pm
Of course everyone wants to see a teardown of that beautiful piece of test gear. :)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: ion on February 04, 2014, 12:08:14 am
+1 for the teardown!

If only the camera was a bit higher on that last shot...
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: SiC on February 04, 2014, 12:52:00 am
I love Advantest kit. :)

Snagged a 3.6GHz Spectrum Analyser with separate Tracking gen for under £500 last year off ebay. Significantly cheaper than a comparable HP, R&S, etc equivalent.

After a bit of googling and help with Google Translate - I found the manual here: http://www.adcmt.com/en/download/manual/ (http://www.adcmt.com/en/download/manual/)

You'll need to create an account and accept their ToC jazz before it'll let you in. Probably could have uploaded it here, but would be no doubt against their ToC's...

Si.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Mavro on February 04, 2014, 12:56:21 am
How does this compare to the Rigol DP832 with precision option?
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: SiC on February 04, 2014, 01:00:42 am
Oh and btw, the TR6142 is the older model. Apart from the datasheet in the video saying so, at some point Advantest changed revisions in their test kit by removing the T at the start - usually the models internals were updated with this change too. I have no idea why the T was dropped off rather than change the model number!

I have found that the schematics of one revision often very similar to the newer model, an element of design reuse. So the schematics in the older TR6142 may line up in some respects.

Si.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: ve7xen on February 04, 2014, 01:51:59 am
Interesting. I've been following Advantest for a while on eBay looking for stuff like this. Damn you Dave! No chance now!

While you wait for Dave's teardown of this box, you may be interested in my teardown of the Advantest R6871E-DC 6.5 digit DMM from the same era. Some interesting construction. Also a similarly weird and unintuitive button interface. https://www.eevblog.com/forum/testgear/advantest-r6871e-dc-6-5digit-dmm-overviewteardown/ (https://www.eevblog.com/forum/testgear/advantest-r6871e-dc-6-5digit-dmm-overviewteardown/)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: aroby on February 04, 2014, 03:48:26 am
I recently came across the blog and I'm having a lot of fun with the videos and learning a ton.  I'm not an EE, so I'm struggling with what this stuff is used for !  It seems that everything is circular - ingenious electronics to calibrate other ingenious electronics.  What's the practical use for this generator other than calibrating other test equipment?

Anthony

PS I'm going to buy an oscilloscope ...
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Dongulus on February 04, 2014, 04:01:54 am
 Dave, surely you could have calculated 0.05% above 1 without a calculator. ;D
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: SeanB on February 04, 2014, 04:18:56 am
+1 for the teardown!

If only the camera was a bit higher on that last shot...

He did say it was a teaser...... Any higher and he would have nothing for the teardown.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: nadona on February 04, 2014, 04:53:56 am
Advantest R6871E-DC 6.5 digit DMM
Why you call 7.5 digit DMM as 6.5 digit DMM, may I ask?
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: EEVblog on February 04, 2014, 04:55:41 am
Dave, surely you could have calculated 0.05% above 1 without a calculator. ;D

Of course, but I'm going through the motions for those playing along at home.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: EEVblog on February 04, 2014, 05:03:56 am
He did say it was a teaser...... Any higher and he would have nothing for the teardown.

I may have tweaked the camera height somewhat...
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: EEVblog on February 04, 2014, 05:06:31 am
It seems that everything is circular - ingenious electronics to calibrate other ingenious electronics.  What's the practical use for this generator other than calibrating other test equipment?

At this sort of resolution accuracy, yeah, that's pretty much the case.
Something like the constant generator is handy for testing LED's for example, but of course the need for this precision is quite niche.
Many of us on here are obsess... err... I mean, interested in high precision gear. It can be a sickness, you have been warned!
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: AlfBaz on February 04, 2014, 05:35:54 am
Many of us on here are obsess... err... I mean, interested in high precision gear. It can be a sickness, you have been warned!
I could stare at an LCD with a digit, followed by a decimal, followed by string of zero's all day ^-^
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Jebnor on February 04, 2014, 05:41:55 am
I for one would love to have a teardown of this device.  The theory of making one seems simple, but I'm sure it's not quite.  I think this would be a good candidate for a Teardown/Theory of operation hybrid video. 

Keep up the good work.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: OrangeJacketGuy on February 04, 2014, 05:53:39 am
4 wire not working properly? Do a teardown and find out. What's this turn-it-on-before-taking-it-apart rubbish? ;)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: ve7xen on February 04, 2014, 06:00:52 am
Advantest R6871E-DC 6.5 digit DMM
Why you call 7.5 digit DMM as 6.5 digit DMM, may I ask?
The meter and most of its documentation seems to think it's a 6.5 digit. 7.5 digit mode is referred to as 'overrange' and I think its absolute accuracy specs aren't quite there for 8.5 digit mode. It does appear to be quite stable out to 7.5 digits, though I don't have the equipment to test it rigorously.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: speffex on February 04, 2014, 07:31:41 am
The 4-wire probably has some relatively high value resistors inside that are shunted by the external wiring. Same as the "sense" wires on some power supplies.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Dr. Frank on February 04, 2014, 08:04:09 am
It seems that everything is circular - ingenious electronics to calibrate other ingenious electronics.  What's the practical use for this generator other than calibrating other test equipment?

At this sort of resolution accuracy, yeah, that's pretty much the case.
Something like the constant generator is handy for testing LED's for example, but of course the need for this precision is quite niche.
Many of us on here are obsess... err... I mean, interested in high precision gear. It can be a sickness, you have been warned!

Precision current sources (0.02% uncertainty/stability) are needed for thermometry, i.e. precise measurement of temperatures, especially in physics experiments at very low temperatures down to liquid He4 @ 4.2K and below.

For PT100 sensors, precise 1mA or 100µA are needed, 10µA and 1µA for Diode based thermometers (e.g. from Lake Shore) and for NTC types as carbon resistors. All that requires 4 point Kelvin measurement, and offset compensation, i.e. a setup with an external current source and a DCV multimeter.

The programming feature of the current source can be used to switch the current off, measuring the thermal offset, which would then be substracted from the measurement with current applied. Very few DMM have this feature, called Ohm Offset Compensation.

As such programmable current sources were very expensive, (Time Electronics, Keithley) and only decade values were needed, I've designed many budget high precision current sources (< 0.01%), which cost below 50 bucks only.

Frank

PS: Yes, I definitely want to see a teardown of this nice unit, please!
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Rubi on February 04, 2014, 09:04:27 am
I've designed many budget high precision current sources (< 0.01%), which cost below 50 bucks only.

Frank


Hallo Dr.Frank

Would you share your designs ?

Grüße aus Wien
Rubi
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: JoannaK on February 04, 2014, 09:04:39 am
Nice to see quick 20min video.. Definitely needs proper teardown. 
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Fraser on February 04, 2014, 03:35:40 pm
I am a total Advantest 'Fanboy' as I used their equipment in my day job and loved it. Advantest is not the most common of brands to be found on the secondary market but you can sometimes be lucky. My inventory of Advantest test equipmet includes several spectrum analysers, optical power meter, two bench frequency counters and several bench multimeters. All of them work fine and are of various ages. Quality is evident in all of teh units taht I have worked on. The greatest problem with buying Advantest equipment is the lack of availabe documentation and servicing information. My R4131 manual cme with service information and schematics but none of my otehr manual have such and even finding a user manual can be very challenging and expensive. I resorted to downloading the Japanese user manuals for some of my multimeters ! Pictures can speak a thousand words.

Advantest equipmet has, IMHO, always had a very good reputation and so tends to hold its value. The Voltage and Current source is usually a very expensive piece of equiment on the secondary market.

If I were to be asked whether I would recommend Advantest over certain other well known brands, I would have a problem. The poor availability of documentation and spares can make them a poor choice when compared to say HP or Tektronix. I still love Advantest kit though and I am prepared to repair it if things go wrong. That is my position but I realise that HP and Tektronix may be more appealing to others. I own plenty of Tektronix kit but only a single piece of HP kit....  The Logic Dart (well 4 of them to be precise). Prices on HP kit can be eye watering due to the known high quality and the repuatation that goes with the name Hewlett Packard.

Anritsu kit is also good, but suffers the same chronic lack of documentation and servicing information as Advantest. I once had to import a service manual from the USA at very high cost as it was only available from one supplier and it was only in paper format.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Nuno_pt on February 04, 2014, 03:41:28 pm
I've designed many budget high precision current sources (< 0.01%), which cost below 50 bucks only.

Frank


Hallo Dr.Frank

Would you share your designs ?

Grüße aus Wien
Rubi

+ 1 here, I would be interested in see the designs, if they can be public available.

Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Dr. Frank on February 04, 2014, 04:02:42 pm
I've designed many budget high precision current sources (< 0.01%), which cost below 50 bucks only.

Frank


Hallo Dr.Frank

Would you share your designs ?

Grüße aus Wien
Rubi

+ 1 here, I would be interested in see the designs, if they can be public available.


Well ok, I'm already collecting some photos.
Will be in the Projects, Designs, and Technical Stuff thread the next days.
Frank
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: robrenz on February 04, 2014, 04:09:01 pm
Thank you!  :-+
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: electronics man on February 04, 2014, 04:10:52 pm
Tear it down
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: e61_phil on February 04, 2014, 07:41:58 pm
Tear it down and tell us how a precision analog to digital converter works :)   (especially this calibration sources with 5.5 and more digits)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: OrangeJacketGuy on February 04, 2014, 11:13:19 pm
*gathers up best Reagan parody voice* Mister Jones, tear down this Voltage Generator!
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: junggwok on February 05, 2014, 01:06:10 am
I made a an offer for a Advantest R6142 over a year ago on eBay, however the seller declined my offer. The unit has been on sale on eBay for over 3 years. It is sold 3 hours after Dave did a video on it. Haha, gotta love his influence.

Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: gemby on February 05, 2014, 09:22:56 am
I made a an offer for a Advantest R6142 over a year ago on eBay, however the seller declined my offer. The unit has been on sale on eBay for over 3 years. It is sold 3 hours after Dave did a video on it. Haha, gotta love his influence.

 :-+
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: gemby on February 05, 2014, 09:26:30 am
Yes, Advantest has great gear, look at this one:

eBay auction: #http://www.ebay.com/itm/Advantest-R8340-Digital-Ultra-High-Resistance-Micro-Current-Meter-/260973667079?pt=LH_DefaultDomain_0&hash=item3cc33e2307

It is realy expensive, but, do i see 10 fA here?
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: EEVblog on February 05, 2014, 10:01:48 am
I've got an R6871E on the way...
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Fraser on February 05, 2014, 10:05:11 am
@Dave,

The R6871E is a sizeable beast but has excellent performance. I own one and IIRC that was the unit for which I imported the user & service manual from the USA. I believe that these manuals are now available for free download.

Update: User Manual is here:

http://www.ko4bb.com/manuals/index.php?dir=Advantest (http://www.ko4bb.com/manuals/index.php?dir=Advantest)

Service Manual is here:

http://www.eserviceinfo.com/downloadsm/62929/Advantest_R6871E.html (http://www.eserviceinfo.com/downloadsm/62929/Advantest_R6871E.html)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Slothie on February 05, 2014, 05:30:07 pm
Just looked on eBay UK and there are a few Advantest spectum analysers for sale at 2-3K and voltage/current sources at 1.5-2K. No 300 dollar bargains! But perhaps they are rarer in this neck of the woods.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: hikariuk on February 05, 2014, 07:11:03 pm
Just looked on eBay UK and there are a few Advantest spectum analysers for sale at 2-3K and voltage/current sources at 1.5-2K. No  bargains! But perhaps they are rarer in this neck of the woods.

Yeah, I noticed that too.  Set up a search anyway, Just In Case :)
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: drtaylor on February 11, 2014, 12:02:13 am
Dave,. I just wanted to comment on the 2-wire vs 4-wire sensing on the R6142. It is common practice to hook the sense leads to the source leads internally with resistors. These resistors are sized so that the sensing error they add is insignificant which is why you didn't see a change in output value. But if you use 4 terminal sensing at the end of your cable, and there is a load there, you will definitely improve the delivery point accuracy by using kelvin connections. For example, let's say the sense and source leads are connected internally with 200 ohm resistors. Then try to source 100mA at 10 V through 22AWG wire. Without the sense leads, the wire resistance alone will cause a significant error. At Fluke we'd debate leaving out the 2T/4T switch as the resistors add so little error in low current measurements.

Obviously Advantest Engineers went with the resistor connected sense leads, so, for low current outputs, you would not see a difference between the 2T and 4T positions of the switch.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: megajocke on March 01, 2014, 08:58:08 pm
I'm not sure I understood the video correctly, but to me it sounded like Dave tested flipping the switch in the constant current mode -- which wouldn't even use the 4-wire connection. So nothing changing is the expected behavior in that case.

There are probably resistors as you say, so even in constant voltage mode it would probably still work, albeit possibly with a little bit of voltage error, if switched to 4-wire sensing while leaving the sense terminals unconnected.

To test the 4-wire mode you'd need a load causing significant voltage drop in the cables and also to operate it in CV mode.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Jebnor on August 08, 2014, 02:30:30 am
Have we had a teardown of this lovely piece of test equipment yet?  Have I missed it?
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: David Hess on August 09, 2014, 11:20:26 am
What's the practical use for this generator other than calibrating other test equipment?

Precision power supplies like this can be used for device characterization and design and development work.  Keithley has a whole business selling precision sources like this.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: David Hess on August 09, 2014, 11:26:58 am
Dave,. I just wanted to comment on the 2-wire vs 4-wire sensing on the R6142. It is common practice to hook the sense leads to the source leads internally with resistors. These resistors are sized so that the sensing error they add is insignificant which is why you didn't see a change in output value. But if you use 4 terminal sensing at the end of your cable, and there is a load there, you will definitely improve the delivery point accuracy by using kelvin connections. For example, let's say the sense and source leads are connected internally with 200 ohm resistors. Then try to source 100mA at 10 V through 22AWG wire. Without the sense leads, the wire resistance alone will cause a significant error. At Fluke we'd debate leaving out the 2T/4T switch as the resistors add so little error in low current measurements.

Obviously Advantest Engineers went with the resistor connected sense leads, so, for low current outputs, you would not see a difference between the 2T and 4T positions of the switch.

Adding resistors or some type of low voltage shunt is also a safety feature.  If a sense lead accidentally gets disconnected, the force voltage will not rise out of bounds possibly damaging the load.  Power supplies with remote sense often include this to protect their load.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: HighVoltage on June 14, 2015, 09:33:54 pm
I got a bargain price on a Advantest R6144 Current Voltage Generator in perfect condition
This R6144 is very similar to the one Dave showed in this video.
But it took me some time to find the operating guide / user manual but I finally got lucky.

Advantest R6144 User Manual:
ds.theatr.us/test-equipment/Advantest/6144_ope_e.pdf

If anyone wants to see some pictures from the inside of this R6144, let me know, and I will open it.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: baoshi on August 06, 2015, 11:53:27 pm
Thanks for the manual. I heard it is possible to hack R6142 into a R6144 by shorting JP1, JP2 and JP11.  Maybe Dave or you can tear down your units to compare?
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: dadler on August 07, 2015, 02:16:34 am
I also have an Advantest R6144, excellent condition, still in perfect calibration. Purchased for peanuts on eBay from a seller that had one left and was liquidating them. Excellent unit.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: HighVoltage on August 07, 2015, 07:43:24 am
Thanks for the manual. I heard it is possible to hack R6142 into a R6144 by shorting JP1, JP2 and JP11.  Maybe Dave or you can tear down your units to compare?
I am traveling right now, but let me take a look when I am back in the lab.
Also, I got one more manual for this R6144, may be I find the 'hack' possibility in there.
Inreresting really is how stable this unit behaves
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: Len on August 07, 2015, 03:21:04 pm
Dave uses his R6142 to troubleshoot a Keithley DMM in EEVblog #777
https://youtu.be/kdCfAR06GeI?t=8m3s
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: kubatyszko on August 16, 2015, 11:45:04 am
Oh and btw, the TR6142 is the older model. Apart from the datasheet in the video saying so, at some point Advantest changed revisions in their test kit by removing the T at the start - usually the models internals were updated with this change too. I have no idea why the T was dropped off rather than change the model number!

I have found that the schematics of one revision often very similar to the newer model, an element of design reuse. So the schematics in the older TR6142 may line up in some respects.

Si.

For the general public, the "TR" models seem to have been made under brand "Takeda Riken" - and many people in Japan still refer to Advantest as Takeda.

The reason for replacing the TR with R was just the brand change.

Also, there's one more brand called "ADCMT" which seems to hold the "old" equipment, at least Adantest seems to direct queries regarding older equipment there...
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: deadlylover on August 21, 2015, 03:21:41 pm
Yep, it seems like any new electronic test gear is now under the ADCMT brand. There are still a few spectrum analysers on the Advantest site, but everything else is ADCMT.

I have both the TR6142 and R6142, they are certainly a little different on the inside and outside. You have to twiddle pots to adjust the TR6142, whereas the R6142 is done err... closed case style in software? (I forget the proper term =P)
Otherwise, most things from "TR" to "R" are the same.

Just a friendly warning, the Maxell backup batteries used inside most old-ish Advantest gear will need to be replaced soon, I had one explode in a nice R6145 Voltage/Current Source/Monitor, taking out quite a bit of the digital circuitry.  :-[
So don't be lazy and replace them ASAP!  :P
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: HighVoltage on August 21, 2015, 03:43:18 pm
Just a friendly warning, the Maxell backup batteries used inside most old-ish Advantest gear will need to be replaced soon, I had one explode in a nice R6145 Voltage/Current Source/Monitor, taking out quite a bit of the digital circuitry.  :-[
So don't be lazy and replace them ASAP!  :P
Thanks for that info
I will take my unit apart and exchange it and at the same time take some pictures.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: deadlylover on August 21, 2015, 03:54:33 pm
Thanks for that info
I will take my unit apart and exchange it and at the same time take some pictures.

I was a bit lazy because I can recalibrate the unit myself any time I wanted, so I thought it was okay if the battery dies a silent death...  :-\

Murphy got me.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: max666 on September 16, 2017, 08:29:56 pm
Have we had a teardown of this lovely piece of test equipment yet?  Have I missed it?

Bump!
Please do a teardown of this beauty, Dave. I think you've teased us long enough.
Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: fiddleback on September 21, 2019, 04:42:49 am
I recently purchased an Advantest R6142, and, having played with it a bit, would like to share what I’ve found.

First of all, the R6142 is, despite appearances, a complete redesign of the older Takada/Advantest TR6142. The board layouts have completely changed, the TR6142 twiddle pots have been replaced with software calibration, and even the reference voltage has been changed. This isn’t to say that the TR6142 documentation is useless. It provided complete schematics and a very detailed theory of operation, both of which the newer R6142 documentation omit. I suspect that there are enough similarities that older “TR” documentation can provide insight into how the newer R6142 works.

(BTW, one lonely pot DOES remain in the R6142 – I think it’s the equivalent of the TR’s R80, which provides linearity correction “by correcting the time constant errors caused by the turn-on and turn-off resistances” of the transistors used to implement the voltage-generating duty cycle. I haven’t had the guts to play with this, since I really don’t know how to measure its effects, and the manual doesn’t provide a procedure.)

I heard it is possible to hack R6142 into a R6144 by shorting JP1, JP2 and JP11.

Thanks for the tip, baoshi! It is indeed true – all you need to do is wave your soldering iron over the R6142, and it will magically turn into an R6144!! (Well, the front panel labels won’t change, but functionally, it literally BECOMES a 6144, and even identifies itself as such while powering on!)

Initially curious about this ‘upgrade’, I noticed that there were two characteristics of the two models that lent credence to the rumor – 1) the parts lists for both units were (so far as I could tell) absolutely identical, and 2) the specifications (accuracy, tempco, etc) for the two units are absolutely identical. The only difference is that the R6144 extends the voltage range from 16 to 32 volts, and extends the current range from 120ma to 160ma. These differences seem hardly sufficient to justify a completely different model and design, especially given the identical performance.

The R6142 comes with U shaped jumpers installed for JP1, JP2, and JP11. But they are cut! So I’m guessing that all of the units are built and originally tested as R6144’s, but then downgraded to R6142’s by cutting the jumpers. (If I remember correctly, one of them was on the digital board – probably something that the CPU can read to determine personality, and the others were near voltage sources – possibly to raise the upper limit of operating voltages/currents.) Here are the jumper locations (in Japanese). http://bbs.38hot.net/thread-15339-1-1.html (http://bbs.38hot.net/thread-15339-1-1.html)

In playing with the R6142 (prior to its promotion to 6144), I came across a peculiarity that’s worth knowing about.

The front panel allows simple manual stepping by a fixed amount (1mv in this case) by pressing the appropriate up-arrow key. It also allows for an automated sweep, simply by pressing and holding the same key. While trying this single stepping, the unit generally behaved as expected – press the button once, and the output increased by 1mv. But every once in a while, it curiously jumped by 2mv. Having noticed this, I set up a sweep, and recorded the voltages output.

The charts below show the results over about the first 1000 1mv steps (0n 10 volt range). The first chart shows that, overall the output appears very linear, as expected. The second chart shows the deviation between the expected voltage and the actual output. Clearly, near 0V output, the output is low by about 3mv. But then the output deviation settles into a curious sawtooth pattern. Taking a look at the magnitude of each step (third chart) shows what’s going on. Each voltage step is about 1mv, as expected. But periodically (about every 126 steps) the step size jumps up to 2mv – just for a single step.


This ‘occasional double step’ behavior seems to occur on all voltage ranges. It is presumably due to some occasional ‘catch up’ being done in setting the digital duty-cycle that generates the reference voltage. I didn’t try it in current mode, but suspect it would behave similarly. Having uncovered this behavior, I just thought I'd share it...


Title: Re: EEVblog #576 - Advantest R6142 Current Voltage Generator
Post by: taichi on October 20, 2019, 06:30:07 pm
I bought a R6144 with Error05 lately. Inside was an exploded battery as the picture attached :'(
 I really recommend people to replace the battery.
I ordered a ER3V battery on AliExpress but it is going to take forever to arrive,  so I replaced it with yet another old salvaged red battery for now.
With some trace repair, and replacing a torn diode, the error is gone and seems working.