Author Topic: 4070L LCR Meter Review/teardown (video)  (Read 7420 times)

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Offline cpuerror

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4070L LCR Meter Review/teardown (video)
« on: June 10, 2015, 09:58:34 am »
This is my review of this LCR meter I purchased from ebay. Bought it on ebay last year and the price has since gone up by another $10 to 33. But money does not always buy you quality.



« Last Edit: June 10, 2015, 10:00:59 am by cpuerror »
 

Offline Lightages

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #1 on: June 10, 2015, 03:13:18 pm »
Thanks for sharing your review. That "meter" looks like money flushed down the toilet. One thing I would try, just to see, is take it apart and get access to the selector dial contacts. Clean the PC traces and the contacts in the dial with some contact cleaner, maybe even use an eraser to give them a bit of a scrub. Perhaps it will work a bit better.
 

Offline Vgkid

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #2 on: June 10, 2015, 05:47:50 pm »
What a crappy meter, would not buy.
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline cpuerror

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #3 on: June 11, 2015, 12:08:15 am »
Thanks for sharing your review. That "meter" looks like money flushed down the toilet. One thing I would try, just to see, is take it apart and get access to the selector dial contacts. Clean the PC traces and the contacts in the dial with some contact cleaner, maybe even use an eraser to give them a bit of a scrub. Perhaps it will work a bit better.

Thats an interesting thought! The more I think about it the more it seems the meter's poor performance could be related to a bad contact. I will need to look at that.
 

Offline retiredcaps

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #4 on: June 11, 2015, 03:43:52 am »
If you can't get steady resistance readings, I would also check solder joints and wiggle the input jacks to see if they are stable.

I can't tell from your video, but if the pcb is dirty or full of leftover flux, a good IPA bath helps.

BTW, current price for this 4070L is around $18 USD + free shipping.

http://www.ebay.com/itm/121443162263

PS.  Your Canadian Tire multimeter was a subject of discussion here.

https://www.eevblog.com/forum/testgear/canadian-tire-mastercraft-dmm-new-and-old-revision-teardown/
 

Offline cpuerror

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #5 on: June 11, 2015, 04:56:59 pm »
I took the meter apart again and did find some issues with contamination and soldering. However after fixing those it's still a piece of crap. I'm going to make another video for it later.
 

Offline Wytnucls

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Offline retiredcaps

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #7 on: June 11, 2015, 05:53:14 pm »
I'm going to make another video for it later.
Look forward to seeing it.
 

Offline cpuerror

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #8 on: June 12, 2015, 03:59:55 pm »
Here is the followup video
I hope you guys dont mind that I took a screenshot from this thread...
 

Offline retiredcaps

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #9 on: June 12, 2015, 11:34:07 pm »
In your video, you mention that the 4070L is out of spec.  If I use Wytnucls' specs from the other thread, they are

Resistance
20 Ohm 1.2%+30
200 -200K Ohm 1%+20
2M Ohm 2%+20
20M Ohm 2%+25
200M Ohm 5%+25
2G Ohm 10%+35

From your video, if we use the Canadian Tire and Philips as being the reference, the 4070L is just barely within specs.

1) Your 1k ohm resistor reads 1002 by the CT and Philips.  The 4070L shows 1022 and 1031.

1002 x 1.01 (1%) = 1012.02. Add 20 counts and you get 1012 + 20 = 1032.  The 4070L, while reading high, is within it stated specifications.

2) Your 1M ohm resistor reads 0.995 by the CT and Philips.  The 4070L shows 1036 before the video cut out at 5:06.

995 x 1.02 (2%) = 1014.9 or 1015 (rounded up).  Add 20 counts and you get 1015 + 20 = 1035.  The 4070L, if you waited long enough, is probably within it stated specifications for this range as well.

Having said that, it is still a loser in terms of build quality and poor speed.

BTW, that green PTC should be around 500 to 1500 ohms.  If it is not, it means it has suffered a high voltage event or bad from the factory.
 

Offline cpuerror

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Re: 4070L LCR Meter Review/teardown (video)
« Reply #10 on: June 13, 2015, 03:08:24 am »
I think Wytnucis 4070 is an older model - the boards are a lot different (his meter even had this weird thing called a 'fuse') so I don't know if the specs are still the same.
Regardless though when I said it was out of spec I was probably speaking more from the heart than from the math on that.
If I can't get the inductance measurement to work on it, the next 4070 video might be an evaluation on its resistance to flame.
« Last Edit: June 13, 2015, 08:35:01 pm by cpuerror »
 


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