Not so long ago we were happy to report annual progress of year 2015, and now it’s time for same once again. There was much more work behind the scenes and few off-line IRL events, covered to some extent in xDevs.com articles. xDevs.com site was created and published in 2008, and continue to be 100% ad-free experimental project to support engineers and share the electronics engineering knowledge. It was not always easy, nor cheap to have new content and projects, but we still here around.

After few months of work to get multilingual interface and support on our site, it revealed high requirements for maintenance. As a result, decision to provide more frequent new content to core English-speaking audience multiple language interface was reverted back to English-only. It will likely to stay this way in 2017 year.

• Started development on universal calibration software to automate gear maintenance/performance report generation.
• New project started, which remain to be secret for now…
• Many new articles, reviews and repairs were performed and uploaded

New content on site

Full list of all new articles in 2016:

That’s total 58 articles added, with few more still in works. If you interested in metrology and ultra-high performance equipment voodoo, be sure to check our Fluke 5700A calibrator review and service and it’s DAC A11 PCBA, Agilent 4142B worklog, interesting 8½-digit Datron 1281 DMM repair worklog.

Few more tests were done on our own xDevs.com KX LTZ1000-based references, covered in Tale 1.

Appreciate support from community and especially from new author, Todd. We already have lot of plans for 2017 to do even more content. It definitely helps, keeping this hobby going to have active discussion on such niche engineering areas. Also Dave L. Jones aka “EEVBlog” created new metrology section on his engineering forum, so many very interesting discussions happen over there. Take a minute and check it out.

Offline events and our own calibration setup.

After a succesful HP 3458A repair big question was revealed how to maintain and keep it’s great specification for use in future projects and repairs.

Since I’ve already got few of best references money can buy, in form of LTZ1000 KX-REF modules it was logical step to use bank of them as DCV transfer standards. For resistance and current multiple stable VPG BMF resistors, with tempco specified ±2ppm/max used. As 3458A allows full calibration with just 7-10 V DC reference and 10 KOmega; resistance standard it’s now a secondary standard for our use.

Few events were established to transfer references and obtain accurate DCV and OHM measurements.

Calibration fest in August 2016, held in USA

It was a one week long event, with next achieved results:

• Fluke 5700A/03 MFC was calibrated to Fluke 732B 10 V, SR104 10KΩ and IET 1 Ω references. All references calibrated under 6 days by accredited labs with sub-ppm accuracy.
• Transfer HP 3458A-002 calibrated same time.
• Keithley 2002 #1 was calibrated to F5700/3458A-002
• Keithley 2002 #2 was calibrated to F5700/3458A-002
• Bank of our xDevs.com KX LTZ1000 references and resistance standard box were calibrated
• Keithley 6514A fixed as side-effect result

Both Keithley 2002’s travelled back with me to Taiwan in checked in luggage without single issue. Test after warm-up revealed same 1 ppm offset between meter, recorded as reference during Cal-Fest event. This allowed to obtain absolute accuracy with ±1ppm for 1-10 VDC ranges and ±2.4 ppm for 1-100 KΩ resistance ranges. Plan for 2017 is to extend accuracy also for current and alternating voltage.

Calibration meetup in November 2016, held in Taiwan

This event was much shorter, just a weekend meet-up in sunny city Taichung. I’ve brought back HP 3458A from owner and took our Wavetek 4920 for a ride.

• Fixed HP 3458A was hand-carried to happy owner
• Fluke 5700A tested using self-check
• Fluke 5720A tested using self-check
• Wavetek 4920M was calibrated to Fluke 5790A with 5720A as source.

Our 4920M travel back to homelab with completed user’s and factory low level calibrations, except the wideband input (none of Flukes had WB option). This brings 4920M as initial reference for ACV from 100 mV to 1000 V with frequency up to 1 MHz.

Summary

During 2016 our website visited 19604 users, with over 7.1M page views. There is no target to capture most views/clicks, no staff involved in full-time project development, so I reveal these numbers just for curious minds. Focus is still to keep high SNR-level on specific niche content we publish, instead going all about broad-topic talks for wider audience. Main focus this year was on high-end test and electrical calibration equipment, such as voltage standards, multi-function calibrators and long scale DMMs.

There are still lot of things to do and improve, so looking forward to next year progress and contributions, targeting to provide even better quality content. Key focus area next year is to work on our own project designs and cowork with other hobbyists, with much more valuable how-to’s and content to be published online! Contact me directly if you have any questions. Every comment matters ;)

We hope to have more advanced experiments, teardowns, repairs and videos in new year. If you wish to publish your findings, articles or lab notes, we are happy to do so. xDevs.com will fund each publication at fixed rate. Details about this will be public soon. Stay tuned!

Happy New 2017!

Ilya Tsemenko
xDevs.com Project