Keithley 2450 source meter alternative

I bought a Keithley and returned it. It was amazingly EMI sensitive.

We buy Keysights, but they are about $5K too.

It would be an intreresting design.

I'm a fan of the HP 4145B. I have one in the rack next to my bench, and have been using them for yonks. Four excellent SMUs plus four sources, all sorts of nice 1990ish comfort features. ;)

It does measurements from tens of femtoamps up to ~100 mA @ 100V.

You do need to take good care of the floppy drive, because that's the only thing that ever breaks.

Really a good gizmo, if a bit klunky for 2021.

Cheers

Phil Hobbs

Yes, I have seen that too

Yes, seems like a small marked though

Very nice indeed.

I am looking for a network analyzer also, think I will buy the Omicron Bode 100. But, the HP4194 is cheaper and better. I am however a bit hesitant to buy a boat anchor, since do not know then the caps fails and it needs repair.

I assume it comes with a CE sticker. If so, somebody cheated.

There are National Instruments SMUs and Keysight SMUs, but I don't have much experience with them. There are also specialist things intended for electrochemistry that are similar, from companies like Bio-Logic

and Metrohm-autolab but watch out for windows-only software that makes them hard to use in automated setups.

If you wanted a project, the eval board for the AD5522 is interesting and inexpensive, and the AD5560 might be good too. I think it would be good if someone makes an instrument based on one of these. With care, it could be quite cheap and good enough for most purposes.

A few years ago I bought a Fluke 8845A 6-1/2 digit bench meter. IIRC it was around $1200 back then and I think John Larkin had recommened it, so I bought one. Quite happy with it.

Side story: UPS did the mother of all union tosses. They literally threw the box over the backyard fence. That's where our concrete basketball court is and it landed almost 10ft behind the gate ... KACRUNCH. Fluke had real smart packaging. Inside the box were two sturdy cardboard frames with thick plastic film mounted on them with high stretch. The meter was held inbetween. I am sure this has saved the meter from being damaged (in which case I'd have made UPS pay for a new one and fly it here).

In hindsight this meter was overkill for me and I could have gone with a

5-1/2 digit at half price but, oh well.

Once in a while you may want to measure microvolts, like the voltage drop in a PCB trace or something. This Fluke is really good at that.

The diode range (1 mA current source + voltmeter) is handy too.

Nice 300 KHz frequency range on RMS AC too. Some DVMs drop off in the audio range.

I have a 6.5 HP34401A, but am looking to invest in more for multiple measurements (and efficiency meas)

The 5.5 Siglent SDM3055 is half the price of the Keithley 6.5, and I am guessing I will never need to have more than one 6.5 DMM:

I can't foresee a need for multiple 6-1/2 digit meters either except for some scientific experiments that universities may be doing. In engineering its more like John said, occasionally you have a nasty short or similar problem where you have to measure microvolts of drop and most of all the direction of it. Battery discharge measurements also benefit from the high resolution because you can arrive at an estimated curve much faster. Except for that I haven't even scratched the surface of what the Fluke 8845A on my bench can do.

We make things like thermocouple and RTD acquisition and simulation boxes, and we have to test and calibrate them. The Fluke is great. The comparable Keithleys and the HP34401A aren't nearly as good.

34401A kicks a lot of noise out of the input jacks, VFD scan I think.

The 8845A sure is nice. I just wish they had put the main power switch in the front. If you just turn it off with the green button the internal heater stays on, consuming quite some watts all the time.

I something similar that with an expensive Agilent spectrum analyzer. During EMC measurements for radiated I kept scratching my head where some of the weird peaks were coming from. Nowhere to be found in the DUT. Then I held a near field probe close to the LCD screen and .. aha!

My little Amazon wiring sniffer thing was fun to wave around various LCD's and VFD's and gadgets.

There must be a lot of cheating going on in FCC and CE testing.

Does Amazon sell near field probes? Not that I need any, got an EMCO kit, but sometimes people ask me about alternatives because the EMCO sets cost a lot.

It can be very tempting to pass the test, get the paperwork and then "economize" the system, mainly by leaving out stuff that is deemed too expensive or cumbersome. I have seen Chinese cables where the molded-on ferrites weren't actually ferrites but just PVC look-alikes. PVC is pretty bad in common mode rejection.

In many of the EMC cases where I was called in I found that it wasn't so much the client's system but OEM parts with class B certs and all that were grossly polluting.

He he, now that was a funny comment :-)

About cheap probes. I got these off Aliexpress:

I got a wire tracker to fix a problem in my kitchen.

It's just a probe and an audio amp/speaker, but it's fun to play with.

I love this answer:

Quote

Question: tracing wire in ground: how deep it can sense the wire? Answer:

106miles

End quote.

Now that's performance!

That's a misprint. They meant 10^6 miles.