2600pcs 1% through hole resistor kit  - The good, The bad, and the WTF - Page 1
Forum section: electronics / general

author: buck converter
author_rank: Regular Contributor
timestamp: August 24, 2017, 01:27:22 am
content: THE GOOD:Resistors came on cut strips, in a nice plastic box, all organized and nicely packaged. Very few strips had bent leads. There were several duplicates of random valuesTHE BAD:5 out of 130 values did not arrive. But i'm probably not gonna need that 47 ohm resistor anytime soon.THE WTF:It makes sense this the way to identify the resistance of a resistor in a kit, in order from most to least accurate:Measure it with a multi-meterdecode the color bars on the resistorread the value on the stripI spot checked a resistor that measured 2.2 ohms, colored 1.5 ohms, and strip labeled 1.8 ohms.Another strip I could not read the label: 6?0K :multi-meter read 500kcolor code read 680Kdid I receive factory rejects?

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 24, 2017, 01:40:08 am
content: Hehe. I ordered 600pcs 1% resistors too for 2 bucks from China. I'll see what I will get once they arrive.

author: Whales
author_rank: Super Contributor
timestamp: August 24, 2017, 01:44:19 am
content: QuoteIgnoring the 1.5 vs 1.8, how did you measure the 2.2?Many common DMM's are pretty useless down in that range. Try shorting your DMM's leads and measuring that resistance, for example.

author: TheSteve
author_rank: Unknown
timestamp: August 24, 2017, 01:51:05 am
content: I bought some 82 ohm 1% resistors from china, so far about 10% of them meet spec.

author: buck converter
author_rank: Regular Contributor
timestamp: August 24, 2017, 02:11:55 am
content: shorting leads read 00.I bought these from Amazon Primewhat is the real disappointment is that I ordered 2 akro-mils drawers to hold it all and I wanted to make a "here in my garage" parody

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 24, 2017, 02:20:25 am
content: Quote from: Whales on August 24, 2017, 01:44:19 amYou can also put your meter into relative mode when shorting the leads so that it zeros out (only if your dmm is equipped with such feature).

author: John B
author_rank: Frequent Contributor
timestamp: August 24, 2017, 02:56:06 am
content: Those cheap massive kits are a total lucky dip. They can be surprisingly accurate, and unsurprisingly inaccurate.Mainly its the tolerance, but that's not a huge deal if you're prototyping stuff and are hand selecting values.I've found they're not 1%, but not quite 5% either. Maybe ~2%.I also collected some data on their temperature coefficient and kept coming up with a number around -294ppm/deg C.The biggest hassle is sorting them out, but once you have a filing system, its nice to go to your library of resistors and pick exactly what you want.Once I even replaced a 3.9 ohm with a 3.6 ohm resistor in a circuit, just went straight to my filing system. What luxury!

author: gamalot
author_rank: Super Contributor
timestamp: August 24, 2017, 03:51:57 am
content: I bought a pack of 1% through hole resistors on Taobao a few months ago, they were very very cheap, and they are accurate.

author: ruairi
author_rank: Frequent Contributor
timestamp: August 24, 2017, 04:00:49 am
content: I don't know guys, resistor lucky dip is not my idea of a good time. I bought my E96 kits through Digikey and it's been great.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2017, 04:19:31 am
content: I bought a cheap pack of 400 a while ago. They were touted as 1% tolerance and when I started measuring some, I found that the +/- 1% was more like +2%/-0%.They were fine for me, since I was only after tolerance better than 5%.

author: TheSteve
author_rank: Unknown
timestamp: August 24, 2017, 04:42:10 am
content: Just an hour ago I received a reply from the seller that I got my "1%" resistors from claiming my meter must be defective and have errors. Now while that is technically possible I am quite sure it is fine.I sent them this picture for fun of one of the 82 ohm 1% resistors:

author: bd139
author_rank: Super Contributor
timestamp: August 24, 2017, 07:58:16 am
content: At least all yours came taped! I got a pack of 2600 0805's that were loose in a bag! Not even taped. Straight in the trash.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 24, 2017, 08:01:53 am
content: Quote from: TheSteve on August 24, 2017, 04:42:10 amHehe, Good one there!

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 24, 2017, 08:04:03 am
content: Quote from: bd139 on August 24, 2017, 07:58:16 amMaybe it was some rejected parts that were not even given a toss about.

author: tszaboo
author_rank: Super Contributor
timestamp: August 24, 2017, 08:59:29 am
content: "You are obviously measuring it wrong, with a obsolete meter that is not accurate enough for 1% accuracy, does not have a cal sticker and you are holding it wrong. "Nice meter.I bought a 0805 1% resistor kit, and I measured and it suprised me, because most of the resistors I measured (about 50 individually) were very accurate. I would say almost all of them were .1-.2%. All of them labeled with value.

author: Zucca
author_rank: Unknown
timestamp: August 24, 2017, 09:38:43 am
content: Quote from: TheSteve on August 24, 2017, 04:42:10 amHe doesn't even know how to manage customer(or use his brain).

author: stmdude
author_rank: Frequent Contributor
timestamp: August 24, 2017, 10:04:33 am
content: Quote from: TheSteve on August 24, 2017, 04:42:10 amDang, dude. Only way that picture could be more perfect is if you had a column of mercury as a reference in the background.

author: TheDane
author_rank: Regular Contributor
timestamp: August 24, 2017, 10:31:58 am
content: When was your meter last calibrated, and do you have the accredited report?

author: capt bullshot
author_rank: Super Contributor
timestamp: August 24, 2017, 10:34:08 am
content: Quote from: TheSteve on August 24, 2017, 04:42:10 amI doubt he gets the point of your picture. Otherwise well done!

author: buck converter
author_rank: Regular Contributor
timestamp: August 24, 2017, 04:06:17 pm
content: Quote from: buck converter on August 24, 2017, 01:27:22 amI checked more resistors, maybe 10% of them are beyond 10% tolerance and another 5% are beyond 20% tolerance.I think I am going to ask for a refund, will see how that goes...

author: bd139
author_rank: Super Contributor
timestamp: August 24, 2017, 04:17:50 pm
content: This thread is seriously making me consider just buying a resistor sample kit from a reputable place.https://www.rapidonline.com/royal-ohm-1-4w-1-122-values-metal-film-kit-62-1504<-- this sort of doodah.

author: TiN
author_rank: Super Contributor
timestamp: August 24, 2017, 04:44:29 pm
content: Quote from: TheSteve on August 24, 2017, 04:42:10 amHowever seller might be right too, there is little chance that your calibration is off.Can't trust those shoddy volt-nuts with stashes of ebay 3458A's, thinking they are all sitting on gold.P.S. I bet that scope with hotski Tek7000 ACQ board right next to 3458A also help to get meter hot and outside of the spec.

author: buck converter
author_rank: Regular Contributor
timestamp: August 24, 2017, 05:11:00 pm
content: Quote from: TiN on August 24, 2017, 04:44:29 pmIn my case, the color markings do not match what he labeled, can't beat that!

author: TheDane
author_rank: Regular Contributor
timestamp: August 24, 2017, 05:19:09 pm
content: No need to spend huge amounts of funds on giant sized dinoaged equipment - a 20 buck ESR tester works great for checking resistors at DC:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/Seems China has trouble delivering quality at the moment, according to page 156 of the topic above.

author: TiN
author_rank: Super Contributor
timestamp: August 24, 2017, 05:30:46 pm
content: No need. But it's FUN! What else reason do you need to justify for 3458A at home?

author: TheDane
author_rank: Regular Contributor
timestamp: August 25, 2017, 06:31:50 am
content: Quote from: TiN on August 24, 2017, 05:30:46 pmAnti-theft ?- I know they weigh in at almost a ton each2'nd house heat source ?- if your 2600 resistors can't dissipate enough heatNerd factorStack-abilityLong term investment2'nd sourced---> $20 component checker, soldering fun + trouble shooting & making a nice looking enclosure for it.Time and money spent, Experience earned - and yeah, FUN equip

author: nanofrog
author_rank: Super Contributor
timestamp: August 25, 2017, 07:34:45 am
content: Quote from: bd139 on August 24, 2017, 04:17:50 pmFWIW,Tayda Electronicscarries Royal Ohm resistors in both PTH & 0805 varieties. So for those that want to build a kit on their own to save on funds, it's worth a look IMHO.To put the cost into perspective, that same Q=2440 kit you linked is just under $30 before shipping (i.e. $.012 per for 1% metal film, 1/4W). They're slow to ship, but that's the compromise for how cheap they are. Just verify there's stock before you order to avoid problems.Granted you still need a binder & some plastic negative sheets (or similar), they aren't terribly expensive. So well under ~95GBP of the kit you linked.

author: bd139
author_rank: Super Contributor
timestamp: August 25, 2017, 07:43:45 am
content: Yeah I've got a massive bag of them from tayda already. The problem is they're not all Royal Ohm ones. Some values are cheap hair-leaded crap which isn't even printed properly. I have considered just stocking up on values from Tayda that are genuine and buying major values from Rapid here in the UK.I don't need 20 of each. Probably 50 each of the E12 set and 10 each of everything else (I get through a ton of resistors)To be honest this was a lame excuse for being lazy and just buying the set

author: tszaboo
author_rank: Super Contributor
timestamp: August 25, 2017, 08:16:31 am
content: Quote from: TheDane on August 25, 2017, 06:31:50 amYou would be suprised. I had a 3458A next to my workstation at work. It was the best multimeter, because it was always there for you. Everyone stole the 34410A-s and the 34401A-s because they are light, easy to grab, and they are accurate enough after a few seconds. Also, you could kiss goodbye to any handheld meter, they disappeared in five minutes if you are not there. Nobody ever stole the 3458A. It is too heavy for that.

author: nanofrog
author_rank: Super Contributor
timestamp: August 25, 2017, 08:31:12 am
content: Quote from: bd139 on August 25, 2017, 07:43:45 amTrue.But I *cheat* and use the search function to specify Royal Ohm.Convenience is nice, but that particular RS/Royal Ohm kit is steep.

author: AndyC_772
author_rank: Super Contributor
timestamp: August 25, 2017, 08:43:09 am
content: Quote from: NANDBlog on August 25, 2017, 08:16:31 amPerhaps you should start up a small business selling DT830 meters glued to paving slabs?

author: Zero999
author_rank: Super Contributor
timestamp: August 25, 2017, 08:47:19 am
content: Quote from: buck converter on August 24, 2017, 04:06:17 pmOther than the low values, <100R, do they all read slightly lower, than the stated values?Make sure you're not touching the meter probes or resistor leads, when you're measuring the resistors, otherwise the resistance of your fingers, will be in parallel with the resistor value, giving a much lower reading, than expected.

author: tszaboo
author_rank: Super Contributor
timestamp: August 25, 2017, 08:58:22 am
content: Quote from: AndyC_772 on August 25, 2017, 08:43:09 amProbably "buying enough meter for the engineers" would also be a solution. 2x 34465A + 1x U1253B + a bunch of cables is about two weeks of salary.

author: TheDane
author_rank: Regular Contributor
timestamp: August 25, 2017, 12:28:53 pm
content: A ton, well.......I'm not too surprised it is heavy, as I have wheeled a lot of te$t equipment around for calibration. That was a few years ago when I worked as a Type-Test Test Engineerhttp://literature.cdn.keysight.com/litweb/pdf/5965-4971E.pdf?id=1000073270:epsg:dow- page 25:Physical characteristics88.9 mm H x 425.5 mm W x 502.9 mm DNet weight: 12 kg (26.5 lbs)Shipping weight: 14.8 kg (32.5 lbs)Who says engineers doesn't get a workout, taking what is needed to get the job done- no running involved though.. Danger Rob'inson

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 25, 2017, 07:52:48 pm
content: Indeed. I would have suspected that the chinese idea of a precision resistor sortiment is one where the colour codes are retroactively corrected using children labour and tiny brushes!

author: amyk
author_rank: Super Contributor
timestamp: August 26, 2017, 04:25:26 pm
content: Those are special resistors with obfuscated markings, used to discourage cloning of competitor's products

author: TheSteve
author_rank: Unknown
timestamp: August 26, 2017, 04:49:49 pm
content: My seller replied telling me my 3458A was bad.I sent 4 more pictures from a 34461A, U1282A, U1733C and a Keithley 2400. Note that the resistors were 1.50 shipped and I'm just having some fun with the seller here, do you think he will ever admit the resistors are crap?

author: Cerebus
author_rank: Super Contributor
timestamp: August 27, 2017, 01:33:07 am
content: I bought a couple of these sets a year back. I've used a few and not noticed anything particularly out of spec, but this topic prompted me to do a bit of random sampling from that batch. They're nominally 1% metal film. Measuring with a Keithley 197, checked against known good standards beforehand, in 4 wire mode, with proper Kelvin clips, everything stabilized at 25 C, just about every resistor I tested in the batch, across a range of nominal values, is about 1% low. Nothing high, and very few near nominal. Odd indeed.If I get in the mood for a couple of hours of tedious work, I might try measuring a couple of whole strips and plot out the distribution I get. Then again, perhaps I may not, we shall see.

author: SeanB
author_rank: Super Contributor
timestamp: August 27, 2017, 01:24:01 pm
content: Probably these were the rejects from the sorting bin, that were popped out after the automatic banding and failing the final automated QC testing. Sold ultra cheap as scrap, as they were not worth redoing the tolerance to 5% per resistor, so were simply dumped as scrap.

author: TiN
author_rank: Super Contributor
timestamp: August 27, 2017, 01:39:41 pm
content: QuoteNever to give up!You found each other, now you need MINTL AccuBridge and quantum hall resistance standard.

author: Cerebus
author_rank: Super Contributor
timestamp: August 27, 2017, 05:49:31 pm
content: Quote from: SeanB on August 27, 2017, 01:24:01 pmI can't be sure without actually doing proper (e.g. extensive and boring) tests and statistics, but eyeballing it they look like the mean and modal values are both just under the -1% mark with a very small spread. If they were, as you suggest, rejects I'd expect two peaks in the distribution and the mean to still be on the nominal value and thus I'd see a lot of +1% as well - I see none, just resistors of different nominal values all exhibiting a -1% shift in value. It's as if the factory had all their measurements off by the same amount, which is clearly wildly unlikely or I got the rejects just from the low side of the process, for several different nominal values, which is even more unlikely.The obvious suspect would be my measurements, but I've got a set of well characterised, hermetically sealed Vishay precision resistors that say my meters are accurate, certainly to a worst case 0.1% absolute error but probably closer to 0.01% in practice. I've got a precision decade box (Vishay 1303) and two precision 10k 0.01% resistors that I use as a 'standard' and they meter out (on the meter I used for these tests) to 10,000.1, 10,000.6and 10,000.6respectively. I think that's enough to instil some confidence in the calibration of that meter.

author: edpalmer42
author_rank: Super Contributor
timestamp: August 27, 2017, 06:11:11 pm
content: How are metal film resistors made?If there's a 'recipe', maybe there was a problem with a batch. Wrong baking temperature, wrong quantities for the ingredients, etc. You could still end up with a nice tight spread of values, but it would be centered on the wrong value.Ed

author: SeanB
author_rank: Super Contributor
timestamp: August 27, 2017, 08:19:55 pm
content: Resistors are ground up to value, while being measured, so these likely were ground up but for some reason they were wrong in anticipating the final value ( helps to speed up the process if you can reliably get the final value as an offset to take machine cycle speed as you do this, instead of going slow till you get there accurately) and these all were rejected values in setting up the line, or they had a bad week and had to dump all the product. that would leave all at one side of the tolerance band, and if they had the value too much the other way they would all be on the high side.

author: PA4TIM
author_rank: Super Contributor
timestamp: August 27, 2017, 08:47:26 pm
content: Quote from: TheSteve on August 24, 2017, 01:51:05 amThat is not bad, they sell them as 1%, that will say: minimal 1% meet specGamalot, That is a very nice Hioki meter

author: nctnico
author_rank: Super Contributor
timestamp: August 27, 2017, 10:31:47 pm
content: Quote from: bd139 on August 24, 2017, 04:17:50 pmBuying cheap resistor kits is a waste of money. What you get is unreliable crap. When I build a circuit I want some confidence that my parts are as specified and work. Cheap resistors often have huge temperature instability.

author: TheSteve
author_rank: Unknown
timestamp: August 28, 2017, 05:03:24 am
content: Seller has given in and offered me a refund, so I don't need to break out even more meters to read a resistor value.

author: TheDane
author_rank: Regular Contributor
timestamp: August 28, 2017, 07:45:45 am
content: Quote from: TheSteve on August 28, 2017, 05:03:24 amCongrats, how much is return postage?

author: bd139
author_rank: Super Contributor
timestamp: September 01, 2017, 11:06:02 am
content: Quote from: nctnico on August 27, 2017, 10:31:47 pmBought a whole dev pack of 1% 0.25W Royal Ohm metal films from eBay (via rapid electronics). Was £85. That's 122 values (full E24 kit) and 20 each.https://www.ebay.co.uk/itm/122365621050These are all 50ppm tempco proper ones. I'd have gone for TE LR1F or Vishay MRS25 but they cost 3x the amount. No spindly chinesium legs on the Royal Ohm ones either.After fecking around with Tayda which doesn't sell consistently branded resistors and I had to wait two weeks and they didn't come with a pre sorted binder I thought fuck it why not. I'm happyThat's 3.5p per resistor which isn't bad considering they are packed and sorted for you so no digging around in bags of shit. I'll make up the money spent in time saved.

author: nanofrog
author_rank: Super Contributor
timestamp: September 02, 2017, 12:20:18 am
content: Quote from: bd139 on September 01, 2017, 11:06:02 amProper tinned copper leads.For those interested in using Tayda, searching for Royal Ohm will eliminate the crap versions.They also carry Royal Ohm in 0805 SMD as well.

author: bd139
author_rank: Super Contributor
timestamp: September 02, 2017, 06:26:03 am
content: Yep. No rustActually if you buy the crap ones from Tayda then you're doing everyone else a favour as they seem to restock with the Royal Ohm units when they go out of stock. I still use Tayda for a lot of things - bought 50 odd TTL ICs from them the other day and a pile of other crap for £30. RS/Farnell cheaping out would have cost me £150!