Hello mnem,
I recently purchased an EDS-88A. It seems pretty nice and since it is for my business, it is a tax deduction. I didn't mind the cost and it seems real nice. I see you also link to the ESR70 too. I may order one of those as these type of devices fascinates me, for what ever reason - simple minds are easily amused LOL.
Do you have much experience with the ESR70? It looks good. I find them for anywhere from $95 (shipping from the US) to $140 (also shipping from the US). I don't know why there would be a $50 difference in where you purchase from. Of course, my brain says buy the cheapest; my gut says to investigate further.
The EDS system machines rely on precise gold plated probe. The other just have regular tin plated clips. Perhaps this is why my experience with ESR machines has been so-so, and actual replacement is the best cap test.
I have an Agilent 4362B and the Kelvin Clip assembly (!!!). I found any cheap ESR meter so much easier to use and rarely fire up the Agilent 4362B. Perhaps it is the Kevin 16089C only using tin plated clips? We are talking very low resistance when measuring ESR.
I have also ordered everything needed (Case, PCB, parts kit, and gold plated probe) to build the EDS-89A Short finder. Do you have any experience with it? There is a youtube video showing the use of the older EDS-88A short finder. It seems amazing. You get a short anywhere on a power rail, it can be impossible to find the short without cutting traces and these days with 6 layer boards, that is mostly impossible. We are talking milli-ohms, or less, in trying to track down shorts. So, I am anxious to try that out too.
Take care and stay safe from the Covid-19 virus.
Dave
Yeah, the EDS-88A does SEEM amazing... actually, too good to be true, especially for a decades-old design. ![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)
I highly doubt it will be nearly as effective in modern complex CMOS circuits where half a volt can turn on multiple junctions and completely bork any in-circuit results. A cap analyzer
that REALLY works in circuit even most of the time has been an engineering
Holy Grail since LONG before I started;
if these people actually had "the magic bullet", I highly doubt they'd be marketing the product the way they do. As you have one, I'd LOVE to be proven wrong, however.
I have used the ESR70+ since it was brammy-spankin' new. In fact, I was in on the first round of preorders, and waited a month and a half for mine. It was def worth the wait, and def worth the extra $30 at the time over the ESR70. I would characterize it as the best such DIAG TOOL I've owned; I get meaningful results in-circuit about half the time, and OOC every time.Your characterization of the contacts is misinformed; the ESR70+ uses a proper Kelvin bridge, with two points of the bridge soldered to each chrome-plated alligator clip, so at most 10-12mm from the point of contact. There is nothing wrong with this arrangement, or with chrome-plated clips in this application, and actually, it yields a more reliable connection in general for quickly moving through a board. Remember, the ESR70/70+ is intended to be a DIAG TOOL; it just happens to be pretty damned accurate for OOC measurements too.
Don't get too hung-up on gold-plating for your contacts; outside of a laboratory environment where you can specify exactly how a connection is made, higher contact pressure is more important and a few electroplated layers of gold doesn't hold up well. Gold-plating is pretty, but it doesn't pay the bills.
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)
For properly characterizing caps OOC, (and sometimes in-circuit as well) I find
the DER-EE DE-5000 as close to laboratory-grade as you're going to get under $300; at around $110 delivered with a full kit of tweezer & alligator probes it is one of the best values in TE out there, bar none. It gives you BOTH ESR and Tan Delta; which means you can use the figures it gives both against the familiar tables technicians have developed for ESR, as well as the Tan Delta figures you will actually find in manufacturer's datasheets. The inherent isolation of battery-operated design coupled with excellent accuracy across operating range (with the DE-5000, very comparable to much more expensive lab-grade gear from the big brands) is why I recommend both for anybody's bench; be it repair or design.
mnem
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