Author Topic: VC8145 thread ... It's here, finally  (Read 81453 times)

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Offline gatoazul

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Re: VC8145 thread ... It's here, finally
« Reply #200 on: December 02, 2016, 04:29:04 pm »
Do you Know whats the reference voltage used in VC8145 (Chip?)
?

 

Online nctnico

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Re: VC8145 thread ... It's here, finally
« Reply #201 on: December 02, 2016, 04:35:36 pm »
It seems I took one of mine apart 4 years ago:
https://www.eevblog.com/forum/testgear/vc8145-thread-it's-here-finally/msg174988/#msg174988

I re-uploaded the pictures today because Imageshack has stopped.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline torch

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Re: VC8145 thread ... It's here, finally
« Reply #202 on: December 05, 2016, 03:27:59 am »
Mine's been powered up 24/7 for about a year now and it seems to be as accurate as when I got it. Not that I have a Keysight to check it against or anything. (I've been meaning to buy one of those inexpensive calibrated voltage standards. Maybe it's time to toddle off to eBay). But comparing voltages to other volt meters and frequency measurements against my faithful Rigol, I don't think it wandered very far. Even the on-board square wave generator seems to be on the money, which would be great if it wasn't limited to 5KHz  :-DD.

I really like the large, clear, easy to read display.
 

Offline ziplock9000

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Re: VC8145 thread ... It's here, finally
« Reply #203 on: December 29, 2016, 08:51:48 pm »
@ k2teknik :
Hello, thanks a lot for suggestion!
The UT70D software runs well and i's good enough for a common use.
It's a pity for the wrong position of decimal point, as You said.
Do you have a link to it please?
 

Offline k2teknik

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Re: VC8145 thread ... It's here, finally
« Reply #204 on: January 23, 2017, 06:11:21 pm »
 

Offline pascal_sweden

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Re: VC8145 thread ... It's here, finally
« Reply #205 on: January 23, 2017, 11:19:56 pm »
It seems I took one of mine apart 4 years ago:
https://www.eevblog.com/forum/testgear/vc8145-thread-it's-here-finally/msg174988/#msg174988

I re-uploaded the pictures today because Imageshack has stopped.

Do you have more than one? How many? :)
 

Online nctnico

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Re: VC8145 thread ... It's here, finally
« Reply #206 on: January 23, 2017, 11:28:57 pm »
I have two and I'm thinking of getting one or two more but that depends on whether I can score one or more of the GW Instek DMMs from the ITT auctions. Sometimes I need more DMMs in a test setup.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline torch

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Re: VC8145 thread ... It's here, finally
« Reply #207 on: March 15, 2017, 05:05:54 pm »
Hi,

im interested in this meter.
How is it going over this years in terms of accuracy?
Could someone who owns this bench multimeter do some accuracy tests?

I'm sorry it took so long, but I ordered this reference module on eBay and it just arrived yesterday. Vendor claims it is measured with a calibrated HP3458A and provides calibration data indicating the actual outputs are 2.50175, 5.00392, 7.50688, and 10.00845 vdc.

I measured the 2.5, 5.0, and 7.5 v outputs 3 different ways: Auto, Rel and manually increasing the range one step.

So, for the 2.50175 vdc standard output, the VC8145 measured:
2.5013 (auto)
2.5022 (rel = -0.0008)
02.500 (manual range)

for 5.00392 vdc standard output:
5.0038 (auto)
5.0046 (rel = -0.0008)
05.002 (manual range)

for the 7.50688 vdc standard output:
7.5069 (auto)
7.5077 (rel = -0.0008)
07.505 (manual range)

The 10.00845 output measured 10.007 in auto and 10.006 in manual, although the rel read 0.

I have had this meter well over a year now and it is generally left on.

Edit: so DCV accuracy works out to +/- 0.02%. Spec is +/- 0.05%+5, so mine is in spec on that range, anyway.
« Last Edit: March 16, 2017, 07:50:06 pm by torch »
 

Offline k2teknik

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Re: VC8145 thread ... It's here, finally
« Reply #208 on: March 16, 2017, 04:10:30 pm »
I checked my VC8145 vith a reference module from eBay too and I cheked all my multimeters, my best one is a Solartron 7150 so I show that one just for a reference.
So my VC8145 is not within spec and that is ok with me, on the other hand I had not seen any drift too.

VoltReference  Solartron 7150            VC8145
  2,50124          2,50152  -0,011%      2,5031 -0,074%
  5,00253          5,00307  -0,011%      5,0068 -0,085%
  7,50426          7,5051    -0,011%      7,5109 -0,088%
10,00489        10,00595  -0,011%    10,014   -0,091%
 

Offline mentaldemise

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Re: VC8145 thread ... It's here, finally
« Reply #209 on: April 18, 2017, 08:25:10 pm »
Could someone provide an image of the CD with the VC8145? I got mine today but the CD is bad so I can't install the app to use the RS232 interface. :(
 

Offline mentaldemise

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Re: VC8145 thread ... It's here, finally
« Reply #210 on: April 19, 2017, 01:28:06 am »
Nevermind. I left the house for 2 hours, returned, and now it won't display anything and the beep is muted. Time for a return.
 

Offline k2teknik

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Re: VC8145 thread ... It's here, finally
« Reply #211 on: April 22, 2017, 08:37:09 am »
.. now it won't display anything and the beep is muted. Time for a return.
Had you try to disconnect the power, wait a minute, reconnect power and then turn it on?
It is a Chinese designed unit sometimes it do strange things.
« Last Edit: April 22, 2017, 08:22:02 pm by k2teknik »
 

Offline sn4k3

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Re: VC8145 thread ... It's here, finally
« Reply #212 on: September 22, 2017, 01:52:53 am »
My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod
 

Offline coromonadalix

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Re: VC8145 thread ... It's here, finally
« Reply #213 on: September 22, 2017, 02:31:27 am »
hi @ll   is there a known calibration procedure for these meters ?
 

Online nctnico

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Re: VC8145 thread ... It's here, finally
« Reply #214 on: September 22, 2017, 09:07:50 am »
My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod
You have to press the select button to toggle between internal and external sensor.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline sn4k3

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Re: VC8145 thread ... It's here, finally
« Reply #215 on: September 23, 2017, 05:31:13 pm »
My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod
You have to press the select button to toggle between internal and external sensor.

Dam that's did the trick. Thank you  :-+
 

Offline ultrablog

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Re: VC8145 thread ... It's here, finally
« Reply #216 on: July 22, 2020, 07:42:24 pm »
Hi

I think my Vici 8145 developed a problem. I wonder if there's a reset procedure or some known issues?
I don't think I should send it in for repair, it came from china and it's a few years old, so very doubtful that is a good idea. The shipping would kill me, and with no guarantee to see it back repaired...

Most of my ranges work. VDC, VAC, mV, mA, 20A, Ω all seem fine. The button for backlight too. But the other buttons adjacent to those react weird. They beep, and the mode changes, so it's not that the button is dead. But the functions are fubar. For example, selecting temp mode displays Ω in the display. Selecting capacity displays mV, and so on. It's erratic. Sometimes it also goes wild beeping. I'm having trouble so determine when that happens if it goes berserk or that it switches ranges continually.

This post is twofold... in a way to warn people, but hopefully someone has a good tip to try and reset it to its working order again...
 

Online nctnico

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Re: VC8145 thread ... It's here, finally
« Reply #217 on: July 22, 2020, 07:53:59 pm »
Perhaps check the ripple on the power supplies. Or the rubber mat with the bushbuttons got dirty and needs to be cleaned. It could be a bad solder joint too; shouldn't be hard to find if you follow the connections to the keypad.

And if you think this is a problem for cheap Chinese products: I had a similar problen on a >$20k Lecroy scope where it turned out a whole bunch of diodes in the front panel switch matrix where broken because they used a diode which is unsuitable for the purpose.
« Last Edit: July 22, 2020, 07:56:48 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline coromonadalix

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Re: VC8145 thread ... It's here, finally
« Reply #218 on: August 17, 2020, 10:53:19 am »
Does anyone made a eeprom dump ??   wanna check something ...
 


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