Datron 1281 Repair/Maintenance

[TiN]

3770 Every time I tried to use them they ended up cracked after just few times. Never ever again, rather overpay for LTC posts that are at least last for years.

[Micke]

3770 Every time I tried to use them they ended up cracked after just few times. Never ever again, rather overpay for LTC posts that are at least last for years.

Yes, I have seen that on the forum  I give this a try, it seems Low Thermal 2758 http://www.lowthermal.com/cables-and-connectors.php are at least 3 times more expensive, and I wonder how long the lead time would be to get them to Europe...    But if the Pomona´s break in the future, I will definitely look for alternatives! Right now I thought "It can not be worse than it is right now..." 
Shame on the manufacturer of the Datron binding post, because other than bad plastics choice it is a great binding post, and I guess very low EMF!

[martinr33]

Usual reminder to also check your local Fluke spares for their posts. If you recycle the washers and nuts, they can save you a lot of money. I thing the basic posts are less than $20 this way (just don't expect a deal on blue).
You have to order at leats three parts - the post, the front spacer, and the rear spacer. Washers and nuts are $3 each. Don't buy the steel start washer for $3. 

[volvo_nut_v70]

Now there is a project for an adventurous soul, 3D print replacement plastics since the post and nut metal is okay.

The original style of post is still available from Fluke since they are used on the Datron/Wavetek/Fluke 4955 Calibration fixture for the Datron/Wavetek/Fluke 9500B

I have dug up the Fluke part numbers for the binding posts.

Blue  = 2053775
Brown = 2053766
RED   = 2053753
Black = 2053748
Green = 2053794

The part numbers are good, the pricing not so good, $127 average each

[Micke]

Those binding posts look exactly like those used in Datron/Wavetek 4600 and 4808, where you have to pull the plastic knob to insert a cable. I have a 4600, and they do feel very expensive!  I wish they could have used those instead in 1281! 

[manganin]

The original style of post is still available from Fluke since they are used on the Datron/Wavetek/Fluke 4955 Calibration fixture for the Datron/Wavetek/Fluke 9500B ... The part numbers are good, the pricing not so good, $127 average each

The mysterious "Datron" binding posts are actually Hirschmann PKI 100 in custom color and plating. The standard version costs less than two dollars each.

[leighcorrigall]

Please do not modify one of the best digital multimeters in the world with cheap binding posts.   

[martinr33]

Summary: you can use a dual coil latching relay in a 1271/81. You don't have to run down the single coil version, which appears to have been gone for decades.

p/n S4EB-L2-6V

The 5V version should also work.


The 1281 and 1271 use a Panasonic latching relay that is impossible to find. It is a 6V single coil latching relay. The single coil design requires that you reverse the coil  current direction to switch the relay, which drives circuit complexity.

This relay is unobtainable. However, it turns out that the dual coil version will work just as well. I found a clear case version at our local junk store. Here's a little video

https://photos.app.goo.gl/oHU1koYftAFRfNT49

The reversible drive current in the Datron circuit can effectively flip the dual coil relay.

[rigrunner]

3770 Every time I tried to use them they ended up cracked after just few times. Never ever again, rather overpay for LTC posts that are at least last for years.

I had this with the older 3770 posts. The newer posts are a darker colour and aren't crimped at the end, allowing the thumbscrew to be removed.
Not broke a new one yet.

New on left, old on right.

[leighcorrigall]

Attached is my first draft of the Datron 1281 button.

EDIT: I removed the original file. See below for the next revision(s).

I plan on printing a few as a favour to a fellow member (rigrunner). It will be the responsibility of the purchaser to prepare the raw part with a primer and a paint coat. Is there anyone else that is interested in such parts? 

Please let me know if there are any revisions to be made and I will update the CAD files accordingly.

[leighcorrigall]

Summary: you can use a dual coil latching relay in a 1271/81. You don't have to run down the single-coil version, which appears to have been gone for decades.

p/n S4EB-L2-6V

The 5V version should also work.


The 1281 and 1271 use a Panasonic latching relay that is impossible to find. It is a 6V single coil latching relay. The single-coil design requires that you reverse the coil current direction to switch the relay, which drives circuit complexity.

This relay is unobtainable. However, it turns out that the dual coil version will work just as well. I found a clear case version at our local junk store. Here's a little video

https://photos.app.goo.gl/oHU1koYftAFRfNT49

The reversible drive current in the Datron circuit can effectively flip the dual coil relay.

Essentially, the S4-L-6V and the S4EB-L2-6V are interchangeable. This component is much more accessible than previously thought.

[wutieru]

When I select cal->spec->adc, I got error 2008 & 2050, the cal failed.
Can anyone tell me how to solve it？

[rigrunner]

When I select cal->spec->adc, I got error 2008 & 2050, the cal failed.
Can anyone tell me how to solve it？

What does pathway PXYY show, is the reading stable?

[rigrunner]

The Datron 1281 PCBs are elegantly mounted with Nylatch panel fasters...

If anyone wants replacements, please let me know.

I got some of the fasteners from leighcorrigall. The 3d printed part he created is a perfect fit. You can't really tell the 3d part from the originals. 

Here are some of the poorly stand offs from my 1281 along with one of the printed parts.

[leighcorrigall]

Attached is my first draft of the Datron 1281 button. I plan on printing a few as a favour to a fellow member (rigrunner). It will be the responsibility of the purchaser to prepare the raw part with a primer and a paint coat. Is there anyone else that is interested in such parts? 

Please let me know if there are any revisions to be made and I will update the CAD files accordingly.

The button appears to be successful in terms of its functionality. It holds well and has the correct dimensions (see the attached image showing a printed button polished lightly with 1200 grit). Aesthetically, there is a slight difference in the roundness which I have corrected in the attached file. The roundness has been changed from 1 mm to 1.5 mm.

If members want to order these buttons for the costs of making and shipping them, please let me know. I plan on making a few more of them for rigrunner and it would be good for them to be done in a batch.

[wutieru]

I checked the maintenance manual, Error 2008 is A/D Fail ,Error 2058 corresponds to Pxyw, the data is unstable and Pxyy is stable.

[rigrunner]

I checked the maintenance manual, Error 2008 is A/D Fail ,Error 2058 corresponds to Pxyw, the data is unstable and Pxyy is stable.

All of the +FR + EXT Zero are related tests.

I spent a long time tracking down a 2058 error. I won't give you the long story.
Try changing the integrator capacitor C505. The original in my 1281 was an ASC X363

Both the Dubilier 730P104X9250 and the Nichicon PWS1633100KG work as replacements
I tried a Vishay MKP1839 but several of those failed after warm up, so stay away from those.

[wutieru]

Thanks a lot.

[Kleinstein]

A change in the integration capacitor may need a new adjustment of the trimmers for the correction circuit for the dielectric absorbtion (DA). The DA for different brands or PP capacitors can be somewhat different.

[rigrunner]

A change in the integration capacitor may need a new adjustment of the trimmers for the correction circuit for the dielectric absorbtion (DA). The DA for different brands or PP capacitors can be somewhat different.

A good point.   

Another thing worth mentioning is C505 orientation. The original ASC has outer foil marking, the Nichicon and Dubilier do not.
You will need to test for the outer foil.




 

[wutieru]

I try to replace C505 with Vishay MKP1839410163.

[rigrunner]

I hope you have better luck with the MKP1839 than I did. I tried several of them and they all failed the same way.
After initial power on all self tests pass and ADC calibration is possible. Leave the 1281 to warm up for 40 minutes or so and try the test and ADC calibration again.
Self tests would pass but ADC calibration would fail.

Power off the 1281 and let it fully cool and re run the tests, exactly the same issue.

I replaced the MKP1839 and tried with the Dubilier and the Nichicon and they work perfectly.

[Le_Bassiste]

...
Another thing worth mentioning is C505 orientation. The original ASC has outer foil marking, the Nichicon and Dubilier do not.
You will need to test for the outer foil.
...

i had foil capacitors that had their outer foil markings on the wrong side. it's a good idea to just always check them.

[bfsy]

Self Cal password ?

[rigrunner]

Self Cal password ?

It's user settable.

Move the digital board jumper to the cal password off position and see if that allows access?

This is the off position