Datron 4950 Multifunction Transfer Standard

[CalMachine]

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  

[CalMachine]

Pictures of the Serialized Cable assembly and 10A Current shunt!

[CalMachine]

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.

[Vgkid]

That is impressive, the case that is. Not the calibrator... 
I wonder if it is a VPG/Alpha shunt resistor as the shunt.

[ManateeMafia]

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.

[CalMachine]

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.

Unfortunately it did not come with any software

[Pipelie]

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,,,,
 

[Pipelie]

more pictures coming

[Pipelie]

continue

[Pipelie]

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.

Unfortunately it did not come with any software

Me either

[TiN]

Aha! My money comes to Pipelie, 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?

[CalMachine]

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.

Unfortunately it did not come with any software

Me either

They 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 them   I'll be posting some here soon within the next few days, as well.
 

Aha! My money comes to Pipelie, 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?

I was wondering what those custom DIP packages were as well.

How would I go about dumping the firmware?

[TiN]

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 my 4920 article for 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..

[Kleinstein]

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.

[CalMachine]

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 my 4920 article for 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..

You 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! 

[TiN]

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.

[CalMachine]

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.

hahaha 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.

[Pipelie]

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 AE
there 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.

[Pipelie]

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.

I have DE1-SOC.
and I've purchased a RPi kit and NI GPIB USB HS should be here this week.

[TiN]

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?

[Pipelie]

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?

I'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 u104
perhaps CalMachine can help.

[TiN]

I'm sure it's bad as combined firmware has junk instead of text strings and values.

[Pipelie]

 

[CalMachine]

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?

I'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 u104
perhaps CalMachine can help.

Once 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

[TiN]

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.