Author Topic: Ultra Precision Reference LTZ1000  (Read 769455 times)

0 Members and 2 Guests are viewing this topic.

Offline TiN

  • Super Contributor
  • ***
  • Posts: 3668
  • Country: tw
  • xDevs.com
    • xDevs.com
Re: Ultra Precision Reference LTZ1000
« Reply #2450 on: November 16, 2018, 12:07:16 pm »
Jumper is same LTZ1000A chip from eBay 3458 A9.
CH1(2) reference had few days runtime before. CH2-CH8 are all first power on (not counting few minutes long test runs). K2002-6 is my 24/7 10V FX reference (uninterrupted power since Feb'18).

I'll need to check CH6 and CH8 units though.

Here I rearrange data to use last yesterday value as 0ppm reference. It's bit easier to see settling time on difference channels.
« Last Edit: November 16, 2018, 12:08:49 pm by TiN »
xDevs.com YouTube | Have test gear documentation to share? Upload here! No size limits, firmware dumps and teardown photos welcome.
 

Offline branadic

  • Super Contributor
  • ***
  • Posts: 1160
  • Country: de
Re: Ultra Precision Reference LTZ1000
« Reply #2451 on: December 04, 2018, 05:07:05 am »
One reference fully assembled and running on 3458A since 400h with 10V boost installed. Another 5 references only buffered are almost ready to go and 4 references are still waiting for their LTZ resistors to arrive. What about the other boards that have been spread over the whole world?

-branadic-
Prema 5000 | 2x Prema 5017 SC | GenRad 1434-G | Tek 2465A | VNWA2.x with TCXO upgrade and access to: Keysight 3458A, Keithley 2002, Prema 5017 SC, 34401A, 34410A, Keithley 2182A, HDO6054, Keysight 53230A and other goodies at work
 

Offline Sprock

  • Newbie
  • Posts: 4
  • Country: de
  • man sollte sich selbst nicht so wichtig nehmen.
Re: Ultra Precision Reference LTZ1000
« Reply #2452 on: December 04, 2018, 08:21:52 pm »
Hello all,
Resitors still in Frankfurt / Germany.
regards Sprock
 

Offline BradC

  • Super Contributor
  • ***
  • Posts: 1553
  • Country: au
Re: Ultra Precision Reference LTZ1000
« Reply #2453 on: December 04, 2018, 08:44:38 pm »
What about the other boards that have been spread over the whole world?

Sitting in a big box with other lonely parts. Resistors have been sitting in a USPS facility in Sanfransico for a week now. They should get here before Christmas, just in time for the festive pause hopefully resulting in some assembly in the new year.
 

Online pansku

  • Contributor
  • Posts: 19
  • Country: fi
Re: Ultra Precision Reference LTZ1000
« Reply #2454 on: December 04, 2018, 09:04:18 pm »
What about the other boards that have been spread over the whole world?

Waiting for parts and the ability to use my right hand for soldering *sigh*
 

Offline SvanGool

  • Regular Contributor
  • *
  • Posts: 120
  • Country: nl
Re: Ultra Precision Reference LTZ1000
« Reply #2455 on: December 04, 2018, 10:45:27 pm »
@Sprock:

Nice card guides, may I ask where you got those?
I assume you are using a bigger enclosure than the Hammond 1455C1210, not (I like the direct ref option you still maintained)?
# Don't hurry, the past will wait. #
 

Offline Sprock

  • Newbie
  • Posts: 4
  • Country: de
  • man sollte sich selbst nicht so wichtig nehmen.
Re: Ultra Precision Reference LTZ1000
« Reply #2456 on: December 05, 2018, 01:00:31 am »
Hi
@ SvanGool,

guides are from scrapp box. The original is from Phönix Type FLP/SKBD.
Yes, you are right the case is bigger. It is the 1455 J 1210  instead of C.
No, all 3 boards will get different boxes. Only one in the black aluminium
with board guide.
regards
Sprock
 

Offline SvanGool

  • Regular Contributor
  • *
  • Posts: 120
  • Country: nl
Re: Ultra Precision Reference LTZ1000
« Reply #2457 on: December 05, 2018, 01:12:54 am »
Thanks !

Mouser has them: https://www.mouser.de/ProductDetail/Phoenix-Contact/2204121 (but not on stock)
« Last Edit: December 05, 2018, 01:19:28 am by SvanGool »
# Don't hurry, the past will wait. #
 

Offline alex-sh

  • Contributor
  • Posts: 16
Re: Ultra Precision Reference LTZ1000
« Reply #2458 on: December 06, 2018, 07:51:38 am »
One reference fully assembled and running on 3458A since 400h with 10V boost installed. Another 5 references only buffered are almost ready to go and 4 references are still waiting for their LTZ resistors to arrive. What about the other boards that have been spread over the whole world?

-branadic-

Mine is still in the box waiting for resistors (group buy on eevblog).

Nice boxes you have. What are they and where did you get them? Are they on Digi-key?
 

Offline Haasje93

  • Contributor
  • Posts: 10
  • Country: nl
Re: Ultra Precision Reference LTZ1000
« Reply #2459 on: December 06, 2018, 08:40:53 am »
Hi!

On page 93 is your awnser. But i have here the link for the cases on Digikey.
https://www.digikey.com/products/en?keywords=1455C1201

Regards,
 
The following users thanked this post: alex-sh

Offline branadic

  • Super Contributor
  • ***
  • Posts: 1160
  • Country: de
Re: Ultra Precision Reference LTZ1000
« Reply #2460 on: December 06, 2018, 08:59:54 am »
Exactly, Hammond 1455C1201 is what the board is designed for. I had a colleague milling the frontpanels for me. The files for them are available a few posts above.

-branadic-
Prema 5000 | 2x Prema 5017 SC | GenRad 1434-G | Tek 2465A | VNWA2.x with TCXO upgrade and access to: Keysight 3458A, Keithley 2002, Prema 5017 SC, 34401A, 34410A, Keithley 2182A, HDO6054, Keysight 53230A and other goodies at work
 
The following users thanked this post: alex-sh

Offline dkozel

  • Regular Contributor
  • *
  • Posts: 102
  • Country: gb
Re: Ultra Precision Reference LTZ1000
« Reply #2461 on: December 07, 2018, 10:39:14 am »
I've ordered the long lead time items but have to finish selecting the last few more basic bits and get them ordered. I've been distracted with figuring out how I'm going to measure these once they're assembled. I don't want to miss the burn-in and do want to measure the three I'm building simultaneously.

I've started testing and warm-up of a pair of 3458A multimeters that I've borrowed (Thread). Along side that I've been looking at different scanner options and managed to find a nice deal here on the forum for a Keithley 7001 with 7011-S cards. They're spec'd for <500nV offset voltage, so >10x worse than TiN's 7168 cards, but I imagine >10x easier to get too. ;) I look forward to the day they aren't good enough for my needs.

Still need to get some cables together, but the last few pages of this thread as well as the various other low EMF threads have been useful there.

Branadic, quick question for you, do the LTZs have >4.2 mm of vertical clearance when in the Hammond case? I'm considering socketing the LTZs if it will work. Also, do you have any plans for how you're using the thermistor? I'm wondering if it's thermally a terrible idea to drill a small hole in the LTZ plastic covers (thanks for the models) and placing the thermistor in direct contact with the case. I have to imagine the thermal transfer would be minimal, but...  :-//

 

Online Kleinstein

  • Super Contributor
  • ***
  • Posts: 4767
  • Country: de
Re: Ultra Precision Reference LTZ1000
« Reply #2462 on: December 07, 2018, 07:25:59 pm »
There is no real need to measure temperature of the LTZ1000 itself. The temperature sensor is on the chip and the temperature is very well regulated - down to the mK range.

Temperature is more effecting the resistors and maybe thermal EMF from the contacts LTZ to copper. Another point is the change in heater power that might effect the reference.

So a temperature sensor would be better placed at the case or at the resistors.
 

Offline branadic

  • Super Contributor
  • ***
  • Posts: 1160
  • Country: de
Re: Ultra Precision Reference LTZ1000
« Reply #2463 on: December 08, 2018, 09:08:07 am »
Quote
Branadic, quick question for you, do the LTZs have >4.2 mm of vertical clearance when in the Hammond case? I'm considering socketing the LTZs if it will work. Also, do you have any plans for how you're using the thermistor? I'm wondering if it's thermally a terrible idea to drill a small hole in the LTZ plastic covers (thanks for the models) and placing the thermistor in direct contact with the case. I have to imagine the thermal transfer would be minimal, but...  :-//

There is for sure enough space inside the Hammond case above the LTZ, but do me a favor and don't use a socket for your reference. I do have a minimal gap between board and LTZ to avoid any stress transfer between them.
The temperature sensor be it a thermistor or a platinum sensor can be used to measure temperature dependance of the whole circuit to verify everthings works a treat. And as Kleinstein already stated, it's not the temperature of the LTZ you want to monitor, but all the other components such as the resistors.

-branadic-
Prema 5000 | 2x Prema 5017 SC | GenRad 1434-G | Tek 2465A | VNWA2.x with TCXO upgrade and access to: Keysight 3458A, Keithley 2002, Prema 5017 SC, 34401A, 34410A, Keithley 2182A, HDO6054, Keysight 53230A and other goodies at work
 

Offline VK5RC

  • Supporter
  • ****
  • Posts: 1989
  • Country: au
Re: Ultra Precision Reference LTZ1000
« Reply #2464 on: December 09, 2018, 05:13:02 pm »
Received some of Mr Pettis' resistors during the week so finished stage 2 of a x6 DrFrank's PCB based Ltz Reference Bank
It is located above TiNs KZ PCB reference bank (plus one old 3458 LTZ reference board alone)
(The 'code' next to each output refers to
   A or C  - LTZ1000 A or C,   
   1 or 2  - op amp LT1013=1 or 2057=2
   Resistors V =vishay. , U= TE's UPW series, P=Pettis Engineering
All have 2 stage linear PSUs
     1st common rail LM38xx,
      2nd stage each LTZ has its own TPS7A4901 ultra low noise in a separate box
All connected to mains UPS
Pomona 3770 posts for Ref 4-15

My Thanks to EEVBlog VoltNuts esp TiN, DrFrank, Edwin Pettis just to name a few.
Robert
« Last Edit: December 09, 2018, 05:15:38 pm by VK5RC »
Whoah! Watch where that landed we might need it later.
 
The following users thanked this post: TiN, Echo88, Andreas

Offline Andreas

  • Super Contributor
  • ***
  • Posts: 2125
  • Country: de
Re: Ultra Precision Reference LTZ1000
« Reply #2465 on: December 09, 2018, 07:15:40 pm »
Hello,

Looks like a serious ageing test.  :clap:

with best regards

Andreas
 

Offline VK5RC

  • Supporter
  • ****
  • Posts: 1989
  • Country: au
Re: Ultra Precision Reference LTZ1000
« Reply #2466 on: December 09, 2018, 08:16:02 pm »
Thanks, references 1 to 9 and `3458` have been almost always switched on since Aug 2017. Reference 8 up until Sept was doing brilliantly but then dropped about 8uV. But now is pretty consistent again - within 1-2uV
My results also may be effected by the 800km road trip my old 3458 went on, for calibration in September - all in spec - so no adjustment. The results before and after cal don't appear to have a consistent trend.
One I get a few months of data from the new references , I read every few weeks I will publish here.
Robert
Whoah! Watch where that landed we might need it later.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf