Datron 4950 Multifunction Transfer Standard - Page 1
Forum section: electronics / general

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 22, 2016, 06:55:53 pm
content: We got some goodies in this week!!! Our Datron 4950 as well as our new 4920M came this week. I am sending them over to the repair side to get caps replaced and a good comb over for old components that need replaced as well. I've asked the repair tech who is going to be working on the 4950 to take some pictures of the tare down and circuits inside! This 4950 has cal void stickers dated 1996, so it hasn't been opened for 20 years.I'm excited to see, as I'm sure many of you are. It is very clean and doesn't look like it has been used much. I can tell it has had its fair share of use, however, from the gold plating wearing off on the banana plugs. I've attached some preliminary pictures that I would like to share with you all! More to come

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 22, 2016, 06:59:17 pm
content: Pictures of the Serialized Cable assembly and 10A Current shunt!

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 22, 2016, 07:00:20 pm
content: The case it comes with and is meant to travel in!It comes with its own temperature and humidity sensor for inside, as well as outside the case.

author: Vgkid
author_rank: Super Contributor
timestamp: December 22, 2016, 07:29:18 pm
content: That is impressive, the case that is. Not the calibrator...I wonder if it is a VPG/Alpha shunt resistor as the shunt.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: December 22, 2016, 08:29:03 pm
content: Nice collection of gear. The top seal looks like it has been opened but most likely to gain access to the battery for replacement.Did you end up getting the software with the kit for the 4950? I am interested in what version of software came with it. The only version I have seen is 3.09.

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 23, 2016, 01:22:33 am
content: Quote from: ManateeMafia on December 22, 2016, 08:29:03 pmUnfortunately it did not come with any software

author: Pipelie
author_rank: Regular Contributor
timestamp: December 23, 2016, 06:09:07 am
content: I got my Datron 4950 this week with the help of Lau, many thanks to him, and of course ,he is The first man i known who tear-down 4950 and get photos.we are all curious about what's inside.here is,,,,

author: Pipelie
author_rank: Regular Contributor
timestamp: December 23, 2016, 06:10:25 am
content: more pictures coming

author: Pipelie
author_rank: Regular Contributor
timestamp: December 23, 2016, 06:12:01 am
content: continue

author: Pipelie
author_rank: Regular Contributor
timestamp: December 23, 2016, 06:15:12 am
content: Quote from: CalMachine on December 23, 2016, 01:22:33 amMe either

author: TiN
author_rank: Super Contributor
timestamp: December 23, 2016, 11:05:40 am
content: Aha! My money comes toPipelie, thank you for pics a lot. Is the unit dead (as caps from hybrids are removed?)?.Based on my little knowledge of Datrons, seems they took 4920, and transmutated it with tweaked Datron 1281 ohm/current boards. They look similar, with better parts.AC attenuator looks very similar to my 4920M, with exception on heated hybrid.What are those DIP-custom packages? Foil resistors? Or ADC FET switches for ramp stage before integrator? They look bit strange.I expected to see two LTZ modules, instead we have same as 4920/1271, single LTZ1000 + LM399 for self-test.Can you dump 4950's digital firmware for poking minds?More voodoo pics please. What's inside the metal shielded compartment? TVC?

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 23, 2016, 02:21:10 pm
content: Quote from: Pipelie on December 23, 2016, 06:15:12 amThey are still extremely nice units, never the less!!! I enjoy playing with this equipment manually via frontpanel more than utilizing software to run tests and walk away, so it's not much of a let down for me.The photos of the circuits are amazing! Thank you for posting themI'll be posting some here soon within the next few days, as well.Quote from: TiN on December 23, 2016, 11:05:40 amI was wondering what those custom DIP packages were as well.How would I go about dumping the firmware?

author: TiN
author_rank: Super Contributor
timestamp: December 23, 2016, 03:59:04 pm
content: If ROMs are socketed, you can pry them carefully out and read with programmer, such as TL866. If soldered, well, than it's more risky job. My request was more to Pipelie as his unit seem to be BER if those hybrids are dead.Make sure you check battery voltage ASAP. You don't want loose manufacturing cal I bet, if it's not already lost.Now, if it runs similar firmware as 4920M, then you can read cal constants values over GPIB with simple code and bunch of DUMP commands. See my4920 articlefor reference. You can't write them back, but at least you will see if original calibration data valid or lost.It's nice to play with buttons, but all these metrology grade gear really meant to be remotely controlled. So jump on RPi+GPIB train, the earlier the better..

author: Kleinstein
author_rank: Super Contributor
timestamp: December 23, 2016, 04:08:37 pm
content: To me these strange looking DIP16 case parts with a glass top look like resistor arrays - possibly laser trimmable. An analog semiconductor of any kind would need a light tight case.I don't see any caps missing with ceramic hybrids.

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 23, 2016, 07:31:07 pm
content: Quote from: TiN on December 23, 2016, 03:59:04 pmYou are very much correct, they are definitely meant to be controlled remotely. And I have looked into the RPi+GPIB blog you did and I am actually looking into purchasing an RPi. I really enjoy LabView, so my end goal is to write my own metrology software here in the next 10 years or so. But for now, the RPi+GPIB interface will definitely be something I can get up and going to join in on the fun quickly!

author: TiN
author_rank: Super Contributor
timestamp: December 24, 2016, 01:48:19 am
content: I was using LabView before, but got tired of connecting lines on ugly non-scaling compatible interface and after small learning curve few lines of python code doing same things but much faster. So for simple stuff , I don't use Labview anymore. Also I can have now PC rebooted without worry to have gaps in week long datalogs...Now, this was a bit secret, but I'm already writing cal software for RPI+GPIB to run performance tests/cal/reports on standard metrology gear for a half year already or so. There is a plan to have it released in 2017. So far software supports 5700,5720,5790,3458,2000/2001/2002/2400/9823,4920M. D4800/4805/4808/1281 support planned.

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 26, 2016, 10:37:53 pm
content: Quote from: TiN on December 24, 2016, 01:48:19 amhahaha yeah I feel you there with the gripes on LabView!I've purchased a RPi kit and it should be here Wednesday. So I should be able to join in on the fun here shortly.You've got me intrigued with your mentioning of your cal software you've been developing. If you need someone's brain to pick who has experience with several different cal software, let me know! I would be more than happy to help.

author: Pipelie
author_rank: Regular Contributor
timestamp: December 27, 2016, 06:07:20 am
content: Brief update:1.Is the unit dead (as caps from hybrids are removed?)?.yes,but when my friend revived it, the unit still can power on,and have a "9005.9 pon tru/compl 0031c8" error on the VFD.when he turn it on again, there is nothing display on VFD.the 9005.9 usually due to the U112 or U105,(static RAM hm62256), I seen it before when i repair my 4920M. the U112 in 4950 also dead same as my 4920M.be aware, if you keep power on the unit for a long time when this SRAM dead,it could cause failure of U110(GAL20V8) and MC68K due to overheat . my unit's SRAM and MC68K are dead. unfortunately, the U110 also dead:(.I was able to read the firmware of the U107(GAL16V8) and U111(GAL16V8),could anybody can share the firmware of U110(GAL20V8,label on the chip is NO.400903-1.1 ) ?2.What are those DIP-custom packages?It should be Foil resistors. resistor array for sure. manufactured by AEthere are six resistor array with gold plated in the unit,but only 5 caps found inside the unit, there is one cap missing.I think these caps are not removed by anybody. just because Glue quality is not good enough.3.Can you dump 4950's digital firmware for poking minds?yes,I'll attach those firmware. read with programmer,which is TL866cs.4.What's inside the metal shielded compartment? TVC?Not 100% sure, but i bet it is TVC. I'll open it in some day.i will upload more picture next time.

author: Pipelie
author_rank: Regular Contributor
timestamp: December 27, 2016, 06:13:11 am
content: Quote from: TiN on December 24, 2016, 01:48:19 amI have DE1-SOC.and I've purchased a RPi kit and NI GPIB USB HS should be here this week.

author: TiN
author_rank: Super Contributor
timestamp: December 27, 2016, 01:29:23 pm
content: u103.18.5.94-401014-2.05b.rar.zip is bad, ROM dump is damaged (bits 1 and 2 are stuck high).Can you check if it's bad ROM, or just error in reading?

author: Pipelie
author_rank: Regular Contributor
timestamp: December 27, 2016, 03:17:34 pm
content: Quote from: TiN on December 27, 2016, 01:29:23 pmI'm not sure it is bad or not, I read it again and compare to the file i uploaded , nothing difference.I can see a lot "06"in ROM U103, that looks odd, but pretty much the same address you can find "00" in ROM u104perhaps CalMachine can help.

author: TiN
author_rank: Super Contributor
timestamp: December 28, 2016, 12:20:07 am
content: I'm sure it's bad as combined firmware has junk instead of text strings and values.

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 28, 2016, 01:25:49 am
content: Quote from: Pipelie on December 27, 2016, 03:17:34 pmOnce our 4950 gets torn down sometime this week or early next week, I'll see what I can do about getting a firmware dump uploaded

author: TiN
author_rank: Super Contributor
timestamp: December 28, 2016, 01:31:37 am
content: I'd also appreciate if you can upload full-size not small pics, so we can droll over the analog magic. More is more, not less. Pretty please. You can find my ftp in my sub.

author: CalMachine
author_rank: Frequent Contributor
timestamp: December 28, 2016, 01:33:21 am
content: Quote from: TiN on December 28, 2016, 01:31:37 amI will most definitely do

author: CalMachine
author_rank: Frequent Contributor
timestamp: January 03, 2017, 11:38:33 pm
content: TiN, I've uploaded some pictures and even a few videos to your xdevs ftp server. More pictures are to come as well! I'm also still working on getting a copy of the firmware.ftp://ftp.xdevs.com/CalMachine%20Datron%204950/If you don't know how to log in, you can look to TiN's signature. Follow instructions there

author: Pipelie
author_rank: Regular Contributor
timestamp: January 04, 2017, 02:17:11 am
content: the part number of the chip in datron 4950 which have firmware.label part number401014 NM27C1010Q400902-1.1 GAL16V8400904-1.1 GAL16V8400903-1.1 GAL20V8Hope this will help, the programmer I used is TL866CS. I try to read the PAL's ROM from 1271/1281/4920, but did't successful.@CalMachine

author: Pipelie
author_rank: Regular Contributor
timestamp: January 04, 2017, 02:20:04 am
content: the resistor array from alpha electronics. and current shunt probably is VCS331 series.

author: CalMachine
author_rank: Frequent Contributor
timestamp: January 04, 2017, 02:23:46 am
content: Quote from: Pipelie on January 04, 2017, 02:17:11 amThat will help a lot! Thank you. Yeah those little ferrite tops to those resistor arrays came off on ours too. Only 1 was still on.

author: Pipelie
author_rank: Regular Contributor
timestamp: January 04, 2017, 02:36:46 am
content: 400903-1.0 (PAL20L8) from 1271 and 4920 is very hot when it is working, you can tell by the color of the label on the chip.I want to backup the ROM of these PAL, but looks like the 1.0 version has been encipher.

author: Pipelie
author_rank: Regular Contributor
timestamp: January 04, 2017, 03:27:08 am
content: more pictures about 400903-1.0 and vcs331.

author: CalMachine
author_rank: Frequent Contributor
timestamp: January 04, 2017, 01:41:22 pm
content: Quote from: TiN on December 23, 2016, 11:05:40 amI am going to work on getting some more pics today. I'm not sure if I will be able to get pictures of UNDER the metal shield, but I know the AC Preamp circuitry resides under there.This 4950 came with every schematic and parts list... so one day, I might get around to taking that to a copy/print shop and have it scanned in using professional equipment.

author: TiN
author_rank: Super Contributor
timestamp: January 04, 2017, 01:44:39 pm
content: That's wonderful. Perhaps you want to write an restoration worklog article about it? I'd be happy to sponsor one of X1801 preamp PSU boards for having that work done

author: CalMachine
author_rank: Frequent Contributor
timestamp: January 04, 2017, 02:31:21 pm
content: Quote from: TiN on January 04, 2017, 01:44:39 pmI am looking into this

author: Echo88
author_rank: Frequent Contributor
timestamp: January 04, 2017, 03:10:52 pm
content: Datron 4950 schematics would be greatly appreciated. I want to compare the DAC-section-schematic to the one in the Fluke 5700A already provided by TiN ( thanks again, learned a lot!).

author: Pipelie
author_rank: Regular Contributor
timestamp: February 19, 2017, 01:20:31 pm
content: Things are shaping up well. but still have a lot of work to do....

author: Pipelie
author_rank: Regular Contributor
timestamp: March 02, 2017, 03:58:59 am
content: quick update:now the unit is power up probably, and running the self-test.again,Thanks to CalMachine who share the firmware of 4950 with me! without he is help this machine will sit in the corner for long long time.PLD :Chip firmwareGAL16V8D-25, 400902-1.0GAL20V8-25, 400903-1.0GAL16V8D-25, 400904-1.0U103,U104:chip firmwareWINBOND W27C010, V2.8

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: March 02, 2017, 04:11:33 am
content: Good news!

author: TiN
author_rank: Super Contributor
timestamp: March 02, 2017, 04:47:35 am
content: Keep us posted

author: CalMachine
author_rank: Frequent Contributor
timestamp: March 02, 2017, 05:27:11 am
content: Quote from: Pipelie on March 02, 2017, 03:58:59 amFantastic!Happy to hear. Yeah, I'm not sure what was up with that first batch of firmware I sent you... Glad the issue is resolved though. I'm glad another one of these beauties gets put to use.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 02, 2017, 07:23:48 am
content: Quote from: CalMachine on March 02, 2017, 05:27:11 amthere are122123 bytes data added by programmer, 67 bytes in the beginning,5556 bytes at the end of the firmware.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 02, 2017, 02:11:22 pm
content: good news!self-test done?and no error code revealed.@CalMachinethe unit need calibration, but I don't known how to calibrate the unit yet. hopefully, it's as easy as 3458

author: TiN
author_rank: Super Contributor
timestamp: March 02, 2017, 05:05:48 pm
content: I think calibration of 4950 painful and tedious, as it's specification requirements are very tight.Unless you don't really care, and choose to settle at uncertainty of no better than your standards.I'm working calibrating 1281 now, and I can tell you, that's not simple plug and play.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 04, 2017, 05:35:04 pm
content: I spent a few hours on calibration yesterday, and turns out the calibration on DCV is easy than I thought.equipment:HP3458ADATRON 4000here is some data I got, I didn't finish the calibration yet, just trying and learning to do the best I can, base on what I have.the result looks pretty good to me so far.P.S.does anybody known where to buy the connector of 4950, I don't have the input cable, and I want to build a cable by myself, but have trouble to find the connector on the market.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 04, 2017, 05:40:54 pm
content: the connector of cable should be fischer 105 series , probably fischer S 105 series. not sure about that.

author: CalMachine
author_rank: Frequent Contributor
timestamp: March 04, 2017, 08:08:46 pm
content: My boss randomly purchased this a few years ago for dirt cheap. We weren't really sure what it was for... but since our acquisition of a 4950, it's come to light! The calibrator output fixture fits our 4708, but not the 4808. If you find a source for the connector, let me know! I wouldn't mind crafting up a set or 2, myself.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: March 04, 2017, 08:16:11 pm
content: The dual connector setup looks like you could connect a 4000(A) and 4200 to the 4950 for a complete calibration.

author: CalMachine
author_rank: Frequent Contributor
timestamp: March 19, 2017, 03:03:21 am
content: Quote from: Pipelie on March 04, 2017, 05:40:54 pmHow is your 4950 coming along? Were you able to locate a source for these connectors? If not, I'll start browsing around.I'll post some results of our 4950's cal here in the next week or so.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 20, 2017, 01:29:23 am
content: Thanks for asking, Been a little busy this month. The 4950 works great, except the ACV/ACI function, I don't have calibrator to calibrate the AC function. what calibrator you use to calibrate ACI and ACV? 4808?I'm still have trouble to find locate a source for fischer 105 connectors. I'm afraid I have to contact fischer to request for quote.

author: CalMachine
author_rank: Frequent Contributor
timestamp: March 20, 2017, 01:43:11 am
content: Quote from: Pipelie on March 20, 2017, 01:29:23 amFor any ACV I use the 4808/4920 and for the ACI I use the 4808/4920/shunts

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: March 20, 2017, 02:03:24 am
content: Kensington Electronics is an authorized distributor for Fischer Connectors. I have used them for Solartron 7081 connectors which are the S 104 style. It was easy to hit their minimum order requirements.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 20, 2017, 02:34:21 am
content: Quote from: CalMachine on March 20, 2017, 01:43:11 amThanks, I'll take my 4950 and 4920 to my friend who have 4808 to calibrate next week.

author: Pipelie
author_rank: Regular Contributor
timestamp: March 20, 2017, 06:54:02 am
content: Quote from: ManateeMafia on March 20, 2017, 02:03:24 am104 style is much easier to find, but not the high voltage 105 series.I got one of these DATRON CABLES last week. borrow it from my friend.

author: CalMachine
author_rank: Frequent Contributor
timestamp: March 21, 2017, 01:33:58 am
content: Thanks Manatee! I'll check them out.

author: Zermalmer
author_rank: Regular Contributor
timestamp: July 28, 2017, 02:15:26 pm
content: Hello,I saw this post before and today I remembered it...Hope that an experienced MTS4950 users can help.In the handbook wavetek specified the transfer stability only for 30 days.Did someone know why the transfer stability period is not specified in combination with the MTS Control Software?The values are ~5 times higher than the 30day period.And related to this period thing... as mentioned above, the handbook only list the 30day period, but the brochure of the 4950(you can find it herehttp://www.rdrelectronics.com/russ/nov12/hunt1.PDF, maybe it's an interesting add on for Tins doc server)lists transfer stability for 30days AND for 90 days.Does the missing period in handbook mean that I can't refere to it because it is only mentioned in the brochure and not valid anymore?Thanks in advance for hints and tips

author: CalMachine
author_rank: Frequent Contributor
timestamp: July 29, 2017, 02:54:56 pm
content: Quote from: Zermalmer on July 28, 2017, 02:15:26 pmIt is. The CAL_CAL specification is the combination of the Transfer stability spec and MTS_CAL software specs.Quote from: Zermalmer on July 28, 2017, 02:15:26 pmAt quick glance, the CAL_CAL just seems to be the Transfer Stability Spec RSS'd with the MTS_CAL spec. If you can determine what kind of algorithm Datron/Wavetek used to extend their 30 day specs to 90 days, I don't see why you wouldn't be able to apply those 90 day specs RSS'd with MTS_CAL specs to get a 90 day CAL_CAL spec.

author: Zermalmer
author_rank: Regular Contributor
timestamp: July 30, 2017, 01:15:35 pm
content: Thanks for the fast answer.I totally overlook that the brochure and handbook gives also the specs for CAL_CAL and MTS_CAL.Still very new to the chapter measurement uncertainty... have still to learn a lot of the details.So the combination and dependencies between all this specs is the key to get the right calculation.ADD:I just see that the MTS Software also must have a own handbook (4950 handbook refers to it e.g. on page 7-1).Is this somewhere available? I had a look to Tin's docs, but the disc images itself doesn't conatin this hanbook... they created them at a time where no one think about having them as ebook..

author: CalMachine
author_rank: Frequent Contributor
timestamp: July 30, 2017, 02:40:56 pm
content: Quote from: Zermalmer on July 30, 2017, 01:15:35 pmI do believe our 4950 came with a MTS software manual. It is entirely in German, however. My sub-elementary German did me no good in trying to use it with the software.

author: Zermalmer
author_rank: Regular Contributor
timestamp: July 30, 2017, 04:13:16 pm
content: Quote from: CalMachine on July 30, 2017, 02:40:56 pmOh... would be nice for me to see it/have it...How much pages did the manual have? Same size as the normal user handbook or bigger?To create a computer with older hardware with Win3.x is normally not a problem here, but having a spare IEEE card to experiment is more the problem.With one eye I track the RPi project from Tin, but the NI adapter is not very cheap.I also read about usefull attempts to use Arduino board to be connected with IEEE...

author: TiN
author_rank: Super Contributor
timestamp: July 30, 2017, 04:38:04 pm
content: Same RPI works well with Agilent 82357B or <khm..> alternative knockoff cheaper pods.I'd say that worthy investment if you plan to frequently use GPIB-interfaced instruments.