Author Topic: Inside the $50 Tekpower UT61E  (Read 893 times)

0 Members and 1 Guest are viewing this topic.

Offline JenniferGTopic starter

  • Frequent Contributor
  • **
  • Posts: 411
  • Country: us
Inside the $50 Tekpower UT61E
« on: November 24, 2022, 07:06:49 am »
I bought this off ebay a couple days back:

https://www.ebay.com/itm/165010229698

Here's a photo I just snapped after opening it.  Seems legit.. Notice anything peculiar? -- I don't.  The seller on ebay said it was the same meter, made in same factory, just different silkscreen for brand logo.



The leads are crap though, and I don't think these are the ones that come with the Uni-T branded probes; the tips are literally as long as the tip of a ball point pen.. and the plastic ends flex like crazy.



It also came with a dead non-alkaline 9V battery.
Test Equip: GDM-8251a, UT61E, Probemaster, Tektronix 2225
Power Supplies: GPD-3303S (w/o overshoot problem)
Soldering Station:  Hakko 926
 

Online Gyro

  • Super Contributor
  • ***
  • Posts: 10172
  • Country: gb
Re: Inside the $50 Tekpower UT61E
« Reply #1 on: November 24, 2022, 11:48:56 am »
Yes, comparing against my photo collection, that looks like a standard Uni-T UT61E (non EU version) meter.

You might want to look at some of Joe Smith's videos on it. He gives strict warnings about not coppying his surge withstand modifications, but he does also covers things like replacing the cal pot (responsible for won't hold cal type posts) with a genuine Bournes, improving cal resolution, improving temperature coefficient etc. I've also copied his ESD sensitivity mod (my own dire warning applies, but that one seems pretty benign).

https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos

There's also the mega UT61E thread somewhere. [EDIT: https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/ ]

« Last Edit: November 24, 2022, 01:34:08 pm by Gyro »
Best Regards, Chris
 

Offline JenniferGTopic starter

  • Frequent Contributor
  • **
  • Posts: 411
  • Country: us
Re: Inside the $50 Tekpower UT61E
« Reply #2 on: November 24, 2022, 02:11:26 pm »
Is that blue trim pot the only pot for calibrating this meter?  What are VR2, VR3, VR4, VR5, CW1 and CW2 for?  I'll try looking for some examples how to calibrate this.
« Last Edit: November 24, 2022, 02:16:37 pm by JenniferG »
Test Equip: GDM-8251a, UT61E, Probemaster, Tektronix 2225
Power Supplies: GPD-3303S (w/o overshoot problem)
Soldering Station:  Hakko 926
 

Online tunk

  • Super Contributor
  • ***
  • Posts: 1099
  • Country: no
Re: Inside the $50 Tekpower UT61E
« Reply #3 on: November 24, 2022, 02:29:02 pm »
There's also a review and teardown of the Uni-T here:
https://lygte-info.dk/review/DMMUNI-T%20UT61E%20UK.html
 

Online Gyro

  • Super Contributor
  • ***
  • Posts: 10172
  • Country: gb
Re: Inside the $50 Tekpower UT61E
« Reply #4 on: November 24, 2022, 02:42:29 pm »
Is that blue trim pot the only pot for calibrating this meter?  What are VR2, VR3, VR4, VR5, CW1 and CW2 for?  I'll try looking for some examples how to calibrate this.

The Blue multiturn pot is for basic DC range accuracy (Vref). The other pots are trims for AC ranges, 10A range, capacitance etc. They're all marked on the silkscreen. The CWs are for AC range frequency response. [EDIT: They are all factory set and don't need messing with]. The multiturn pot is the one that is a cheap clone and worth replacing with a genuine Bournes.

It's worth reading the ES51922 datasheet [and the UT61E schematic]. No EEPROM to worry about on this one!

« Last Edit: November 24, 2022, 02:52:31 pm by Gyro »
Best Regards, Chris
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf