The rabbit hole of multimeters - Page 1
Forum section: electronics / general

author: walcen
author_rank: Contributor
timestamp: July 07, 2011, 04:39:57 am
content: I returned a Jaycar multimeter the other day cause it was a complete piece of fecal matter.I thought it was a reasonable one as it was marked down from $79 to $59, BUT IT WAS,NT !!!.And before you ask, Yes I pulled it apart and trust me, it wasn't worth a photo.And it also suffered from a scratchy continuity buzzer but it seemed to work ok when testing traces, I think it's caused by poor conductivity on the test probes.Dave, You my friend have ruined my life, I was perfectly happy living in the matrix believing that a multimeter is a multimeter is a multimeter but there you have it, you threw a bunch of red pills and a bucket of cold water at me and here i am sliding down the rabbit hole of multimeter's.I have discovered however that if one need to do capacitor testing, even expensive multimeter's have a limited range. there must be only so much you can fit in one meter I suppose and therefore one would probably be better off purchasing a dedicated capacitance tester.The one I sent back to Jaycar only measured to 100 uf, what's the good of that when even a hobbyist muck around with values much higher.So my conclusion is that Dave is good,Dave is wise, have at the very least two meters and remember the word of confucius, He who bye's good quality tools cry,s once, He who bye.s cheap stuff cry,s many times.regards to allWal

author: Armin_Balija
author_rank: Regular Contributor
timestamp: July 07, 2011, 05:48:01 am
content: I know that feeling. A year ago I would've bought any old multimeter to get me by. Now I look at a few of those cheap chinese ones laying on my desk and I just wanna take them apart for components..then I think about if the components are even worth the hassle. They're probably junk anyway.Either way, I scrounged up 180 bucks and got myself a fluke 179 on ebay.. I really want an 87-5 but I just don't have the cash for that right now. Either way, the only thing that's really going to bug me about the meter I just got is that it can't measure uA... and I know I've heard it a thousand times from Dave..get one with a uA range.I'm going to get a couple 50 dollar multimeters that he suggested to get that range. I wanted the Fluke for accuracy, reliability, hardiness, and great warranty.

author: EEVblog
author_rank: Unknown
timestamp: July 07, 2011, 09:19:50 am
content: Quote from: walcen on July 07, 2011, 04:39:57 amYou're welcomeDave.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: July 07, 2011, 09:50:46 am
content: Well, Dave it does influence our way of thinking.I got damaged too..But I love sliding down in rabbit holes, all my life.

author: ipman
author_rank: Regular Contributor
timestamp: July 07, 2011, 09:57:26 am
content: @Armin_Balija: it depends on what purpose you use your multimeters. Had the 179 for many years as main meter, still have it as second, and did not miss that feature at all in general purpose hobby repairing of stuff broken at home.Now I have one which has it, but never used it anyway.

author: Vertigo
author_rank: Regular Contributor
timestamp: July 07, 2011, 12:00:50 pm
content: indeed, likewise i should thank you dave for saving me from that stuffas i found the videos before making my purchase, and i have made a farbetter choice then the pieces of crap i was looking at before.so thanxz Dave

author: Armin_Balija
author_rank: Regular Contributor
timestamp: July 08, 2011, 06:04:54 am
content: Quote from: ipman on July 07, 2011, 09:57:26 amIt's my first brand name multimeter, we use flukes at the University and they're great..just a bit worn from over the years. I was really hoping uA wouldn't come into play until I started buggering with some complex digital circuits.How does the 179 perform in terms of general analog electronics..nothing high power.

author: ipman
author_rank: Regular Contributor
timestamp: July 08, 2011, 06:37:30 am
content: I did not trobuleshoot low-power circuits, just normal ones, but considering this job, I did not miss any feature on 179.

author: PStevenson
author_rank: Regular Contributor
timestamp: July 09, 2011, 10:53:54 am
content: yeah Dave wrecked me too. before I stumbled onto Daves youtube channel a while ago I was quite happy with some piece of shit with through-hole components complete with a transistor checkernow I have 3 fluke meters, trying to get a forth.87III11277III can't stop looking for them on eBay, I'm going to end up with hundreds

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: July 09, 2011, 11:58:44 am
content: Quote from: PStevenson on July 09, 2011, 10:53:54 amThat's a wild estimationEven so I think that if you come close to the number of eight ,the hunger moves away.

author: ivan747
author_rank: Super Contributor
timestamp: July 09, 2011, 01:53:02 pm
content: Quote from: Vertigo on July 07, 2011, 12:00:50 pmYeah, Dave, you convinced everyone to get a DECENT electronics lab, not just a lameass lab.

author: Fraser
author_rank: Super Contributor
timestamp: July 09, 2011, 02:14:01 pm
content: I also wish to thank Dave for opening my eyes to kit that is top quality and also that which is excellent VFM.As a direct result of Dave's helpful comments I now own a beautiful NOS Fluke 87 Series III and a Rigol DS1052E (upgraded to 100MHz). I always used pretty decent (if a little old) test kit and was content with my Hameg 20MHz CRO and Uni-T multimeters....then I found Dave's Blog and the rest is historyI still buy quality 'used' 1990's test kit (all known and respected brands) but it's nice to have a new Fluke multimeter and reasonable spec DSO as wellYou have my thanks Dave.

author: PStevenson
author_rank: Regular Contributor
timestamp: July 09, 2011, 09:31:38 pm
content: Quote from: Kiriakos-GR on July 09, 2011, 11:58:44 amI'm aiming for hundreds haha but yeah I reckon 8 is a good nice round number then I can move onto the special function metersI already went through an oscilloscope phase. I love test equipment, even if I have no use for it, if it looks cool I'll get it anyway

author: eternal_noob
author_rank: Regular Contributor
timestamp: July 11, 2011, 04:11:46 pm
content: Quote from: walcen on July 07, 2011, 04:39:57 amWell, if you find yourself measuring electrolytic capacitors all the time, I think you should consider spending money on a proper capacitance meterwithESR capability, one of the most important thing to measure on large electrolytic caps.But at the same time, I think this ''equipmentism'' is stepping over the line sometimes. Since I'm not a pro, I rarely do bulk measurements or have the need to do it with high accuracy, so I often turn to very simple methods and DIY equipment for the task.For example, those few times throughout a year I need to do capacity measurements on electrolytics, I do charge/disharge time measurements. The accuracy of this method is more than good enough for me. The tolerances on electrolytic caps are large anyway.I think both hobbyists and pros need to go to the library and dig up the old books from early to mid 1900's and relearn some of the neat tricks they did when you simply couldn't buy ''everything''. I have a book from Terman, ''Measurements in Radio Engineering'' (1935), that I have picked up a lot from. Maybe I'll put this book on the the scanner some day and share it with you all.So there you have it. There's no way I'm going to spend hundreds (or thousands) of dollars on meters I rarely use. Absolutelyno way, bud!! I would rather spend my money on components to tinker with.

author: PStevenson
author_rank: Regular Contributor
timestamp: July 11, 2011, 05:06:25 pm
content: I'd like to read that book however I don't think in todays word of digital complexity we can rely on tricks from 1935, maybe some may come in useful sure.some people just like to have every tool for any job they may encounter and I'm one of those people, I love being in a dark room lit up by that pale green glow of 10 oscilloscopes waving awayespecially in winter cause those scopes do get hot.

author: eternal_noob
author_rank: Regular Contributor
timestamp: July 11, 2011, 05:47:45 pm
content: If one only does digital stuff, of course not, but we still need analog electronics and would probably do for a long time.So all you do in your shop is staring at the glow from the screens and displays?A little story:I actually managed to get quite a few people pissed off on a discussion board some time ago, when I suggested a simple bridge, with brass nails hammered into a board for measuring a variable capacitor (a guy wanted to measure one for a radio project). The AC generator was a cheap radio from China. People went totally bonkers when I claimed 5 percent accuracy of this godforsaken thingy, until another guy there actually copied the bridge and could confirm the accuracy. Then everything was cool..In fact, it's very hard to get horribly wrong results from a measurement bridge.You gotta laugh at people sometimes and at that instance i was the last one.

author: gregariz
author_rank: Frequent Contributor
timestamp: July 11, 2011, 06:14:36 pm
content: Quote from: eternal_noob on July 11, 2011, 04:11:46 pmI agree, I think the multimeter thing is quite overdone. Even cheap chinese meters today are better than meters made not so many decades ago. Certainly good enough for designing most circuits even if not good enough to survive repeated drop tests. Dave showed everyone a $50 extech that was going to be fine for 99.9% of folks in his video's.As far as books go, I agree with that to a large extent. Terman is a classic, even though its old there are still gems in there like coupled circuit and inductance calculations. I'll think you'll find a pdf already floating around the web! In my experience alot of people are coming in from the computer side only these days so their analog background is simply not there. And often their discrete digital design is not much better. In fact the only bankable skill I see most graduates have today is the ability to use a C compiler and some microcontroller. We really need to use boolean logic? Plus there are alot of tricks to the trade in the analog world that are difficult to pick up from a book. Usually I look for the early writers on any topic as I find they usually know the why's and how's of the technology. Later writers tend only to write about what they have found using an abstracted tool. for example DSP books written in the 80's and early 90's tend to give you simplified code to work from. These days all you'll get is a library and some pics of them using a FPGA. Likewise with radio - all you'll get is a circuit using some particular chipset common today - no discrete designs you can customize, let alone the worked out design equations. Likewise with discrete transistor design, most modern books on this topic are beyond hopeless. I was in my local Fry's yesterday flicking through an electronics book which was really just this is a transistor, this is a tuned circuit - I felt like vomiting on it. I was at Barnes and Nobles flicking through a Signals and Systems book which gave only a single sentence of nonsense before introducing the z-transfrom. Just a load of crap - I'm sure most people who write these books I see on the shelf these days haven't done it. I'm equally sure they don't really understand it either. Conversely if I pick up one of my favourite transistor design books, I'll see its by a Senior engineer in some industrial company. Its like night and day.

author: eternal_noob
author_rank: Regular Contributor
timestamp: July 11, 2011, 08:13:07 pm
content: Quote from: gregariz on July 11, 2011, 06:14:36 pmA nice multimeter is nice to have, but I don't trust the inductance and capacitance ranges of many of the cheaper meters, and I would prefer they just cut that crap out and left the user with a good frequency counter or a good mechanical range switch instead. And, as the thread starter mentioned most of them have limited measurement range.A counter is much more useful in my opinion since it's possible to do highly accurate L and C measurements with one. It's always good to know/learn how to measure things and WHY it is sometimes done in a specific manner.What good does it do when you have just bought a brand new ''Fruke'' multimeter for 400 grands, sticking the probes across the filter choke of your tube amplifier and measuring 35 Henry, when it's in fact 5 under load, due to ''Incremental Inductance'' (True Inductance under DC and/or other complex loads)? Or, do the stupid mistake as I did, when I tried to wind a 10uH RF choke on a ferrite toroid intended for power use? Yes the choke actually measured 10uH on a meter that had a 600KHz internal oscillator. Of course it didn't' work at 4MHz. SheeeshHere the old books comes into good use, since the new ones often is just pure nonsense as you wrote.

author: PStevenson
author_rank: Regular Contributor
timestamp: July 11, 2011, 08:24:26 pm
content: Quote from: eternal_noob on July 11, 2011, 05:47:45 pmonly on weekends haha got to live life on the edge you know!

author: Semantics
author_rank: Contributor
timestamp: July 12, 2011, 02:26:20 pm
content: Quote from: PStevenson on July 11, 2011, 08:24:26 pmYou can tell folks you're working on your indoor tan.

author: PStevenson
author_rank: Regular Contributor
timestamp: July 12, 2011, 02:45:57 pm
content: I just like to pretend I'm the incredible hulk in the green reflection haha

author: Ronnie
author_rank: Regular Contributor
timestamp: July 14, 2011, 12:49:36 am
content: Quote from: walcen on July 07, 2011, 04:39:57 amThat is why the first multimeter I purchased was a Fluke 179 for US$216 (including 8% California sales tax). Though my first multimeter was a Soar ME-540 made in Japan given by my Dad during the late 80s

author: Ernie Milko
author_rank: Regular Contributor
timestamp: July 16, 2011, 10:49:30 am
content: I think many people view the eev videos, and then rush out and buy a Rigol scope and a Fluke 87v meter.I've noticed a real upsurge in 87v prices on ebay in recent years. People will pay £200 for an 87v, yet an 87iv or a 187 (both of which are a better spec then the 87v) go for considerably less.You've only got to look at Jim Williams (RIP) home or Linear Tech bench, to see that you don't need the very latest digital gizmo.A trap a lot of newbies fall into is getting lost when they don't understand what their brand new 'Wizzo' is telling them. ISTR a somewhat heated debate here a while back, involving a Fluke 289 and a user who clearly didn't know how to use it.I take a slightly different view with test gear; with an (extremely humble) nod to Jim Williams.Most of my test gear is very old. But it all works. I've repaired most of it.This means I trust it, and know how to interpret the readings. And by repairing it, I've learned from the experience.Test gear isn't just 'something to use', its an extension of the DUT

author: Unknown
author_rank: Unknown
timestamp: July 16, 2011, 05:51:05 pm
content: I agree. It does depend a bit on the particular piece of test gear, though. Old analog scopes are very capable, for example. Old digital scopes not so much, especially for beginners (limited memory, sample rate equals lots of aliasing). Good old DMM's can be excellent value, as long as you don't need industrial safety features (not talking something like the 87IV here, more like the Fluke 8000 series). Even an analog VOM can still be useful, if you're used to it. Not sure if I would recommend beginners to buy one, however.

author: Chet T16
author_rank: Frequent Contributor
timestamp: July 16, 2011, 06:20:23 pm
content: Because of Dave i now have a rigol scope and atten 938D soldering station and 858D hot air station and a few other bitsI still have my POS $3 "FUKE" multimeter however...I just can't decide on what to getI have 100 euro to spend for my birthday from my wife though!