Antique General Electric 100A 0.2% Shunt

[@samsami9014]

amazing whatever you are doing... very important information i get it so far keep up tge good work joe... thanks a lot

[@zyspan]

Careful with your wedding band!

[@zx8401ztv]

Thats one heavy duty shunt, i think i would clean the terminals and put it in a box with car battery cables and a second pair of thin wires to check the drop across it. Thats a beast :-D

[@joesmith-je3tq]

It's a bit too large to fit inside the UT61E. However, in the ending clip, figure it's a 0.0005 ohm shunt. The signal to noise when trying to make mA measurements with it is poor as you could see. But, let's say it was 0.1 ohm. You can imagine measuring mA would be pretty easy. Using FC3 on the UT61E to drive an N-FET, that is then used to drive a couple of Ps (I know you don't like relays) across the 9 ohm shunt. Add one more op-amp. We could greatly improve the burden of the 61E in all ranges. The dominant resistance would be the fuse but if a person were just using the meter to look at 50ma and lower, the burden would be in the 50mV and less for all ranges. SIBA has 1 and 2A versions of that fuse that would help. Start going up higher, the tiny Ps may need to be beefed up.

[@zx8401ztv]

LOL i dont think the shunt would fit in the ut61e, unless it was dr who's tardis :-D. You have a warped sense of humor, i like that :-D :-D Somehow i can mentally forward fast 3 years.... the ut61e has become the size of a fridge, and you are still improving it LOL. Ooow i dont hate relays, think about how handy the common square types that (when we were young) we added super duper spot lamps to our cars, and the relay was the switcher. .... Oh only me then lol :-D

[@joesmith-je3tq]

The other option is use the 0.01 ohm shunt for the mA ranges.

[@zx8401ztv]

Now that would make the burden vdrop very low :-D. But more stages of amplification and suppression capacitors to stop the whole circuit howling between stages. A nice idea though :-D

[@joesmith-je3tq]

Notice the added caps when I changed the amp for that 0.0005 ohm shunt? That's getting down in the muck. In practice, it's not a good use for these cheap breadboards. 0.1 ohm would be a very doable and I think I could pull off using the 0.01 shunt but would need to be a lot more careful how things were connected. The 61E just needs a 1"^2 prototyping area.

[@GadgetReviewVideos]

I wonder if the older shirts are copper plates, and the paint is to prevent oxidation on the copper plates?

[@joesmith-je3tq]

TC of copper is really bad which is why I hit it with the heat gun. I suspect manganin. I do believe it is paint and that it was added to prevent oxidation.

[@doctorazizli]

Hi Joe. What is the model of your LeCroy oscilloscope on the bench in this video?

[@joesmith-je3tq]

It's an old 64Xi.

[@doctorazizli]

How would you describe it in comparison with new low end digital oscilloscopes? Does it worth to buy one?

[@joesmith-je3tq]

I don't own any new low end scopes to compare it with. IMO the 64Xi is a good general purpose scope for it's age. Anything I have bad to say about it is with the mechanical packaging. This was a private clip I made to show transfer rates to a PC running LabVIEW and calculating an FFT. kzbin.info/www/bejne/j5K9ZKh-nN2om9WIhis was a video I made were I was attempting to use it to measure power.kzbin.info/www/bejne/ZmWsaKF-dsR7rq-Ihere was also some older videos were I compare it with my antique LeCroy 7200.kzbin.info/www/bejne/p5TZepJojsuHmrc

[@doctorazizli]

Not surprisingly, old school guys, I love this. :) İt seems that Mr Carlson also has no modern oscilloscope. Thanks for the response, Joe. 👍

[@joesmith-je3tq]

I've watched a few of his videos. The one with the EGR was pretty interesting.

[@JasperJanssen]

You're moving around the clamps a lot without zeroing, that seems to be an issue for these D.C. Clamps.

[@joesmith-je3tq]

You are correct about the need to zero them. I also posted a fair amount of data on the temperature drift. These are really bad. However, you seem to be missing that the offset on these are in the 10s of mA and we are measuring several Amperes. The drift and offset are down in the muck and there is not much need to be so careful.

[@Universal_Craftsman]

"I am looking for a high end meter to run, looking at Gossen, I am leaning towards the Ultra." "High end" didn't age well with this one 😃 I first thought that the Gossen is a Multimeter without compromises, and then, getting through your tests, one by one the flaws appeared and I was completely shocked.

[@joesmith-je3tq]

I think several of us were shocked but that's why we look at them.

[@RobB_VK6ES]

How do you rate the UniT clamp meters Joe , good bad meh ?

[@joesmith-je3tq]

First, I have never plugged leads into them. I use these for a current clamp only. The reason I have them is because the can measure with 1mADC res. Not hacked or aligned, it's pretty much the only UNI-T product I have ever recommended people buy if they need that low current DC. It's pretty good. Hack the software, it's very good. Hack the hardware and you can really turn it into something useful.

[@joesmith-je3tq]

These are links to other videos I made showing the UT210E. Again, to be clear, I am not suggesting that ANY other UNI-T has any value to me. I specifically want the UT210E for the 1mADC res in the 2ADC range.kzbin.info/www/bejne/hpjLnX2Yl89ppqOcttps://kzbin.info/www/bejne/Zp3cfpx3gMuCoLecttps://kzbin.info/www/bejne/mJa7n3mmhbWqnZY

[@uN1Qu3DZ]

You're being a bit harsh on them - i own two UNI-T meters, the UT60E and UT70A (which i bought mainly for its inductance measurement capabilities, but it is a good all-rounder and can stand quite a bit of physical abuse). When i bought the UT60E i asked the clerk at the store to plug it into the 230v mains and switch it thru all ranges. He was reluctant but did it anyway, i have been buying from them for a long time. It didn't blow up so i bought it. Measured up to 1.6kV with it no problem. Also the frequency meter which clams to go up to 20MHz IIRC, goes up to the full 4999 count. Discovered that when i measured a 48MHz firewire clock. I do have two gripes with it and that is the SLOW autorange and even slower capacitance meter, but i have a dedicated capacitance meter so it's no big deal. Other than that everything works including the datalogging capabilities. I have owned the 60E for ~6 years and the 70A for ~5. I would not trust the CAT IV 600V rating tho, but i am not an industrial electrician, i use it for hobby work. It is also a bit sensitive to RF - but then again everything is when you have a 50W transmitter next to it. I did need to clean the range switch on the 70A and blew a trace inside, but that was due to my own incompetence of bridging the mA fuse and forgetting about it.

[@joesmith-je3tq]

All the meters are treated the same. If I am being a bit harsh on them, I am being a bit harsh on every meter I have looked at. I did a few videos about how stupid it is to bridge a fuse. You may want to watch them. I like the UNI-T UT210E because it actually does something very useful for me out of the box. It is cheap and measures mADC with a clamp that fits in one hand.

[@uN1Qu3DZ]

I did watch the bridged fuse video last month. That was a long time ago, i do know better now.