Question on equipment setup and Dmm  - Page 1
Forum section: electronics / beginners

author: Housedad
author_rank: Frequent Contributor
timestamp: January 18, 2017, 12:40:23 am
content: Hi, I have decided to get back into the world of electronics after being out for 30 years or so.I have read quite a bit to try to catch up, but there is a lot to study, of course. But that is why it it is fun to have as a hobby.Anyway, I have now received a Rigol DS1074z oscilloscope and unlocked it, a Instek SFG 1013 Function generator, a couple of GPC-3020 Power supplies (used from Ebay), a GPC-3030D (Used, Ebay), and a Weller WES51. I have a lot of the small tools and stuff and I a couple of mega 328 component testers from Ebay.Anyway, now I'm down to the DMM. The ones I have around the house are Junk and I needed to get something for the bench. I basically have it down to either the BK 2709B or the Bk 393. I'm kind of torn between the two but am leaning toward the 2709B due to cost. These will never leave the bench, so they don't have to be Fluke or any kind of field durable. Any suggestions or thoughts?I have read in a couple of threads that two DMM's are recommended nowadays. Is that true?

author: rstofer
author_rank: Super Contributor
timestamp: January 18, 2017, 12:55:52 am
content: The thought is that measuring voltage without measuring current is of little value. Some (maybe all) bench meters can do both measurements at the same time and have dual display capability. But it can also be done with two meters.Consider the small signal amplifier: It would be reasonable to want to measure base voltage (or current) and collector current (or voltage drop across the collector resistor).I have the EEVblog Bryman BM235 meter along with a Fluke 189 and Vichy VC99. I haven't read the VC99 reviews or watched the videos but it seems to be pretty decent. In addition, I have a couple of Simpson 260 V-O-M meters. I do not have a bench quality meter.So, yes, you will want more than 1 meter at some point.If the reviews aren't horrible, the VC99 meter is very attractive at $23:https://www.amazon.com/Signstek-Manual-Digital-Multimeter-Ammeter/dp/B00FFYPUTMActually, a pretty good review:https://www.eevblog.com/forum/testgear/vichy-vc99-multimeter-review-and-teardown/

author: Lightages
author_rank: Unknown
timestamp: January 18, 2017, 03:15:03 am
content: The VC99 is built down to a price for sure. The first thing you want in a measurement instrument is confidence in that it is reading correctly. The poor construction and bad quality control with the solder splashes show that it won't last long and might have problems. Many people will also tell you that if a meter has a transistor test socket, then you should look elsewhere. It is a mostly useless gimmick that robbed costs away from more important considerations.If your budget doesn't allow for more money, the good alternatives are things like the Uni-T UT139C or Amprobe AM5X0 series. IMHO I would stay away from the Extech EX series as they have had a run of bad quality control (made by CEM, have a look for recent discussions). The BK meters are OK but older designs and some have reported them to not be that durable.If you are thinking of buying a BK2709 for close to $200, then consider the many other multimeters available that people have recommended here many times. There are many to choose from that are reliable and not high priced junk.

author: rstofer
author_rank: Super Contributor
timestamp: January 18, 2017, 03:58:51 am
content: Quote from: Lightages on January 18, 2017, 03:15:03 amAccording to the video, the meter is superbly accurate - better than the Fluke it was compared with. Accurate readings won't be the problem. it might be useful to have one of those DMM calibrators regardless of what meter you own.The solder splashes could be cleaned easily, if they exist. The transistor socket is a shock hazard (as I understand it) and, as the review author said, he wanted to use it for electronics, not electrical power. No problem, I have several other meters for power.Is there a tear-down video for the BK2709?For $24, the VC99 would be a great meter for electronic level work. But it would be good to remember the limitations.

author: nanofrog
author_rank: Super Contributor
timestamp: January 18, 2017, 04:12:24 am
content: Quote from: Housedad on January 18, 2017, 12:40:23 amYou can do better these days than the BK Precision models IMHO.Depending on budget and needs, you would do good to considerBrymen. You can get it in the US with a Greenlee label, or from TME.eu in Poland, the latter being less expensive (shipping is reasonable at ~$20, and is very quick).The least expensive meter I'd recommend would be a Uni-T UT139C, which you can get for under $40 shipped (example; plenty of reviews both here and on YouTube). Nice little meter, and it has decent protections so you can use it on mains. For a top-end meter that's easy on the wallet, I'd recommend a BrymenBM869.Personally, I mix & match meters; meaning, I might use one meter to measure temperature, while those measuring voltage and current do not have that particular function. Gets you a lot of functionality this way for less cash (i.e. no need to spend $$$ on all top-end meters when one and a few decent 6000 count units with the basic functions will do).

author: rstofer
author_rank: Super Contributor
timestamp: January 18, 2017, 04:18:48 am
content: So, I ordered the calibrator just to see how the meters I already own check out. I wonder how the Fluke 189 checks out.

author: retiredcaps
author_rank: Super Contributor
timestamp: January 18, 2017, 05:31:35 am
content: Quote from: Housedad on January 18, 2017, 12:40:23 amFor $100, the BK2709B did very well in Dave's $100 meter shootout back in 2010.If cost is a concern, you might be able to snag an used Fluke 83 or Fluke 77IV on ebay/craigslist/pawn shop for $50 USD or less. Both are unloved because they are not True RMS, but otherwise very good meters. And yes, I have managed to get the deals I write about with patience.

author: Lightages
author_rank: Unknown
timestamp: January 18, 2017, 05:32:23 am
content: Quote from: rstofer on January 18, 2017, 03:58:51 amThe Centech free meters are accurate out of the box, most of the time. What counts is if something stays accurate and reliable over the long term. Sure it might be perfect this year, but what about 3 years from now? Solder splashes should not be there and require you to disassemble your meter completely to make sure that it doesn't have problems. If the first thing you need to do is disassemble your equipment to make sure it is built correctly, you shouldn't buy it. What else did they screw up?Also, read the reviews on the amazon link, 20% give it less than 3 stars.......Quote from: rstofer on January 18, 2017, 03:58:51 amThe UT139C is a much better buy IMHO, even if it is twice the price.

author: rstofer
author_rank: Super Contributor
timestamp: January 18, 2017, 05:50:50 pm
content: Quote from: Lightages on January 18, 2017, 05:32:23 amI just opened my meter and I didn't get any solder splashes... Clearly, the reviewer did. What we don't have is a teardown of all the other meters. Solder splashes are bad!You can't make an argument about 3 years or any other duration. If you don't have it calibrated on an annual basis, you can't make any claim about any meter. Sure, I feel all warm and fuzzy about my Fluke 189 but I don't really KNOW that it gets the right answers. Same with my eevBlog Bryman - who is Bryman? Never heard of them... Realistically, it could be just a high-dollar cheap meter. I bought it for the logo, maybe it came with quality and accuracy but I haven't checked.As to Amazon reviewers: Some of them ought to take up another hobby. Buy a $24 meter and then complain about the battery compartment? Seriously? I swear, some of the reviewers just want their name in lights.QuoteThat UT139C seems like a nice alternative. I have no idea whether they are accurate and I haven't seen the teardown. There must be one around somewhere...I also bought several Harbor Freight meters - $5 each:http://www.harborfreight.com/7-function-digital-multimeter-90899.htmlPretty useless except when they aren't. One of them served as a battery charge tester on my sailboat for 10 years of more. I used 3 of them when I helped my grandson with his Science Fair project. We did Ohm's Law and he actually came in First Place. The meters looked good glued to the project board. It looked like real science... Knobs, dials, displays with numbers - real science.

author: Housedad
author_rank: Frequent Contributor
timestamp: January 19, 2017, 03:59:50 am
content: Thanks for all the help, folks!!!I finally have all of the major equipment sorted out. A friend found a Instek 5-1/2 bench multimeter on Ebay for me and I ended up buying even more stuff there at prices I just could not turn down.So I have or on order:New instruments:Rigol Ds1074Z scope,BK Precision 2709B MultimeterInstek SFG 1013 3 MHz function generatorUsed instruments::Instek GDM-8251A 120,000count bench multi-meterRigol DG1022 25mhz function generatorInstek GOS-6112 Dual trace analog oscilloscope.Instek GPD-3303S Triple Linear DC Power SupplyTwo Instek GPC-3020 Triple Linear DC Power Supplys (analog meters)All of the used stuff I got looks to be in really good condition and they were either a really nice deal and most were at killer prices. Ebay is great if you negotiate a bit. All total I spent under a grand for both new and used combined.They may not be the latest or greatest, but if they all work, then I hope it will be a decent bench to work at.I guess I'll post a pic when it all comes in.

author: Lightages
author_rank: Unknown
timestamp: January 19, 2017, 05:12:03 am
content: Quote from: rstofer on January 18, 2017, 05:50:50 pmWhere the F*&) did you get the spelling "Bryman"? Only if you had heard someone say it instead of reading it would you write it that way or you are trolling. You have a Brymen BM235 from Dave but claim to never have heard of them, and you misspell it? I smell troll.......... There are dozens of threads here on EEVBlog forums about Brymens and their rebranded models from other manufacturers. I would also like to point out that I did not say anything about Brymen at all in my responses.Quote from: rstofer on January 18, 2017, 05:50:50 pmhttps://www.eevblog.com/forum/testgear/new-trms-uni-t-ut139c-dmm-is-available-now/https://www.eevblog.com/forum/testgear/uni-t-ut139c-multimeter/msg663881/#msg663881

author: tggzzz
author_rank: Super Contributor
timestamp: January 19, 2017, 09:40:27 am
content: Quote from: Housedad on January 19, 2017, 03:59:50 amAt worst you will learn what youneed(cf want) for your next project!I returned to electronics after 20 years, and I was surprised, pleased and dismayed at how little had changed. The changes I noticed were:microcomputer based projects were the same (8/32 bit plus C), except they were much smaller cheaper and with much better development/debugging environments"RF" had moved a decade higher in frequencyADCs/DACs were markedly improved in speed and resolutionnanopower "energy stealing" components are becoming possibleeasy/fast locating and buying componentsandmost of what I had learned at university was still valid(The last point is intended for those that believe going to university has little value!)

author: Housedad
author_rank: Frequent Contributor
timestamp: January 19, 2017, 09:40:44 pm
content: Quote from: tggzzz on January 19, 2017, 09:40:27 amThanks. That is good to know. So everything is still an extention of the past. At least I have the basic knowledge to start with. Now to update myself!

author: tggzzz
author_rank: Super Contributor
timestamp: January 19, 2017, 11:10:14 pm
content: Quote from: Housedad on January 19, 2017, 09:40:44 pmThe fastest way start that is to get The Art of Electronics 3rd editions and look at the tables. If you have earlier versions, don't throw them out.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: January 20, 2017, 12:19:00 am
content: You can get an Agilent/Keysight U1252B on eBay brand new in box right now for $200. The seller is asking $225 but came back at $200 when I offered $175. I took it. This is a $425 meter. I prefer it to my Fluke 87V, except for the latch on the continuity is not fast unless you set the range to MegOhms

author: rstofer
author_rank: Super Contributor
timestamp: January 20, 2017, 12:22:44 am
content: Quote from: Lightages on January 19, 2017, 05:12:03 amIt's a typo... Or, actually, I thought it was BrymAn and it's really BrymEn. Big deal! People don't often spell my name right either.I had never heard of them. I did buy two of the eevBlog units just to support the cause but I wouldn't have known or cared who made them. I still don't know anything about the company, I have never looked at their instruments (rebadged or otherwise) and I can actually say, I have never heard of them - even though I bought two. No videos, no reviews, just bought 'em to support Dave. Turns out they are pretty decent but they are no substitute for my Fluke 189. Still, they're just great when working on heating systems up in the attic.In my view, if you want a decent DMM, you buy Fluke. Everything else is just something else. DMMs start at $5 and work up. The buyer needs to figure out how much they want to spend on a hobby.

author: Lightages
author_rank: Unknown
timestamp: January 20, 2017, 02:05:36 am
content: Quote from: rstofer on January 20, 2017, 12:22:44 amIf that is the case, then I apologize for my outburst.Quote from: rstofer on January 20, 2017, 12:22:44 amBrymen meters have been discussed many times here on the forums. Dave has done a review of some Brymens in one of his videos. Brymen is the ODM for some Amprobe (same parent company as Fuke), Greenlee, Extech MM series, and some others. Their meters are built and independently tested to meet the current CAT ratings and IEC requirements. The BM869S for example is rated at CATIV 1000V.