Where to get certain resistor values? - Page 1
Forum section: electronics / beginners

author: Analog Kid
author_rank: Super Contributor
timestamp: December 30, 2024, 02:25:59 am
content: I guess I'm only familiar with (and only have) resistors in the "E12" series.Shopping online, and I'm looking for a resistor kit that has values that I currently lack.One of them is any multiple of 3: 30Ω, 300Ω, 3KΩ, etc.What series has these values in it? and where can I get them for $cheap$? (1/4 watt variety)Jameco doesn't seem to have any of these.

author: themadhippy
author_rank: Super Contributor
timestamp: December 30, 2024, 03:21:21 am
content: QuoteE24

author: TimFox
author_rank: Super Contributor
timestamp: December 30, 2024, 03:23:36 am
content: Otherwise known as 5% values.3.01 k, etc is a 1% value in the E96 series.

author: Analog Kid
author_rank: Super Contributor
timestamp: December 30, 2024, 03:37:37 am
content: Quote from: themadhippy on December 30, 2024, 03:21:21 amSo where's a good place to buy these?

author: TimFox
author_rank: Super Contributor
timestamp: December 30, 2024, 03:52:09 am
content: I think that almost everyone sells them.5%, 1/4 W resistors are extremely common: what tolerance do you need?Certainly DigiKey, Mouser, etc.Mouser has cheap 1% Yageo metal film axial-lead resistors for $0.12 in singles and $0.046 at quantity 10.

author: Analog Kid
author_rank: Super Contributor
timestamp: December 30, 2024, 04:12:56 am
content: Tried Mouser.Through-hole kits.Result: 1 product.No go.Any more suggestions? aaaaargh ...(BTW, 5% is fine. Must be through-hole, though.)

author: jpanhalt
author_rank: Super Contributor
timestamp: December 30, 2024, 04:19:59 am
content: I have reluctantly bough some resistor kits off Amazon. So far, the ones I have tested were within spec. Why Amz? Small order, fast shipping, and no shipping. Total cost can be less than fixed rate shipping from DigiKey. I do not make getting electronic parts from Amz that cannot be tested a practice..Here's one kt with 3.0...https://www.amazon.com/Minidodoca-Tolerance-Resistors-Assortment-Compliant/dp/B0BNWSCCJZ/ref=sr_1_14?crid=3AG11RNL2PT0W&dib=eyJ2IjoiMSJ9.9auwJDD1kOZT_VAxZUQqvymkv_CjOZwl-NmqNsu9WmQpvkCoyp9zH8bABZDuLzbOpwnmoVG3CnrSc1v2rwIZ-8GEIWF7-fAQkMk6Ysona1zfaXgwLm9377rDiDoH6tyrQUJG3Li5S0qijDuSMOsogStB_wghKmfwOQBQa09eS_lgUYkPhwHqxukRdvTQyVrEoDaKuKc1CUssDR3baHlVMn8iCqBimsp64m_gM8U__NY.Xt_T9qo4u9NV72G0S_KhUpw5qMKP7A62G8ZP9tKPMJ0&dib_tag=se&keywords=resistor%2Bkits&qid=1735531978&sprefix=resisttor%2Bkits%2Caps%2C143&sr=8-14&th=1

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: December 30, 2024, 09:49:32 am
content: Another vote for Amazon. I bought a kit of 2600 x 1% 1/4W metal film E24 series resistors a few days ago. My bag of old 5% E12 carbon film resistors were in serious need of replacement. Similar kits are listed on eBay, but Amazon is so convenient and "free" next day delivery too.https://www.amazon.co.uk/dp/B07ZPVMT9MSJ

author: magic
author_rank: Super Contributor
timestamp: December 30, 2024, 09:58:57 am
content: Did you scratch the blue paint to see if they are actually metal firm?Lots of those Chinese kits are carbon film resistors in blue paint.Metal film resistors also exist, but it's a lottery, as usual.Also, 3.0 = 1.8 + 1.2.

author: golden_labels
author_rank: Super Contributor
timestamp: December 30, 2024, 10:28:01 am
content: RoyalOhm MF006FFE012KIT, perhaps something from TE Connectivity RES KIT series (CFR16,LR1RS,CFR25RS, …).But why would you buy an entire set, instead of just the values you need? I can understand if somebody starts a professional lab, but to just refill missing values?

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: December 30, 2024, 10:37:21 am
content: Quote from: golden_labels on December 30, 2024, 10:28:01 amIt is expensive to buy individual resistors, when you add the postage. Buying a kit which includes most of what you need for several years worth of projects makes sense.You also can “select on test” from a good selection of resistors, if you need to tweak any values.The Amazon kit of resistors only cost a few percent more than the small order charge from Mouser, not a problem if buying several expensive parts too, but for something with 2 or 3 transistors it works out very expensive.Incidentally, I scraped the paint from one of those Amazon resistors and it looks like shiny metal film underneath.SJ

author: Analog Kid
author_rank: Super Contributor
timestamp: December 31, 2024, 05:03:04 am
content: Quote from: jpanhalt on December 30, 2024, 04:19:59 amOrder placed, with no reluctance at all. (At that's what my reluctance-ometer says.)BTW, that horrible URL can be shortened tohttps://www.amazon.com/Minidodoca-Tolerance-Resistors-Assortment-Compliant/dp/B0BNWSCCJZwith no loss of function. (Cut off everything starting with/ref=.)

author: tooki
author_rank: Super Contributor
timestamp: December 31, 2024, 10:09:56 am
content: Quote from: Analog Kid on December 30, 2024, 04:12:56 amYou also need to select “axial” in the Termination Style, not just “through-hole”. Then it’s 7 products, not 1.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 01, 2025, 02:12:57 am
content: Thanks. I tried that and got 6 results; close enough, I guess.But Mouser definitely isn't the place to get a resistor kit, at least not for me:There's one item that's less than $10: 400 resistors, 20 values.Doesn't show the values or the tolerance.The rest of the items listed start at ~$200.I'll stick with my Amazon order that's on the way (~$26 incl. shipping for more than 3K pieces of 1% resistors, presumably not fake ones).

author: Konkedout
author_rank: Frequent Contributor
timestamp: January 01, 2025, 05:23:31 am
content: How do you plan to use these resistors? Do you plan to lay out pcbs or will you be hand wiring or using proto boards of some type?If you will be using pcbs, then go with surface mount. Cheaper, easier to swap, smaller. In my opinion, small axial resistors (below 500 mW or 1W) are obsolete for use on pcbs.My hands have never been very steady but I use 0603 and larger chips with no problem. (I use a small 0805 footprint for 0603.)If you are more comfortable doing so, start out with 1206 chips. That is what we did when starting with surface mount in the 1990s.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 01, 2025, 05:44:56 am
content: Nope, no surface-mount for me.I'm a hobbyist. I typically use bare perfboard (no copper) and hand-wiring.Most of the stuff I use is obsolete (DIP chips, etc.).

author: Haenk
author_rank: Super Contributor
timestamp: January 01, 2025, 09:58:19 am
content: Quote from: Analog Kid on December 31, 2024, 05:03:04 amBTW, that horrible URL can be shortened tohttps://www.amazon.com/dp/B0BNWSCCJZThose chinese resistors vary in quality, can't beat the price though, and in general they are better than "good enough". The "1%" tolerance is sometimes not met, more like 1.5% or so - maybe that's why the are so cheap (factory rejects), however coming from carbon these are a largely better choice.Just make sure to buy the 1/4W, not the 1/8W - those are really flimsy.

author: jpanhalt
author_rank: Super Contributor
timestamp: January 01, 2025, 12:40:38 pm
content: Quote from: Analog Kid on January 01, 2025, 05:44:56 amI use solderable breadboards laid out like the non-solderable versions. TH work fine; however, 805 size chips fit very nicely on the 0.1" (2.54mm) spacing. See attachment above the SOT23-3 pads. I just received the JLCPCB boards discussed here (https://www.eevblog.com/forum/eda/design-solderable-breadboard/msg5744611/#msg5744611) and am anxious to try them.

author: tooki
author_rank: Super Contributor
timestamp: January 02, 2025, 09:37:56 am
content: Quote from: Analog Kid on January 01, 2025, 02:12:57 amIm sure they’re close enough in value for most hobby use.What really annoys me about the cheap resistor kit I got on eBay or AliExpress years ago is how stupidly thin the leads are. Practically impossible to use in a breadboard because the leads bend when you look at them wrong, but if you do manage to insert them, they’re too thin to be properly retained.Let’s hope yours are better.

author: magic
author_rank: Super Contributor
timestamp: January 02, 2025, 10:59:58 am
content: Let's be serious - they won't be.I recall that bd139 recommended some online store somewhere in Asia where one could order Royal Ohm THT resistors cheaply in quantities of 50 or 100.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 03, 2025, 12:56:43 am
content: Quote from: magic on January 02, 2025, 10:59:58 amI'll let y'all know once my package arrives.

author: Benta
author_rank: Super Contributor
timestamp: January 03, 2025, 01:19:21 am
content: For passives, I mostly go to DigiKey.

author: golden_labels
author_rank: Super Contributor
timestamp: January 03, 2025, 11:36:53 am
content: magic, Analog Kid: the primary problem with suspiciously cheap imports is not quality. It is consistency. You may score a decent deal, but you never know what is coming in the next order. And repeatability is of no less value than quality. What you get from established brands is the high chance of getting the same product each time over years. When you buy unknown thing from no-name middleman, you get whatever they themselves managed to fish this month for lowest price possible. Usually they themselves hardly know, what are the items they sell.I suppose it also depends on the perspective. If one is a beginner or a hobbyist on budget, and uses very small number of components, then “a resistor” is probably equally good no matter where it comes from and how many of them have issues. I never had trouble buying indicator LEDs from China. If some out of hundreds don’t work, it’s not an issue in this scenario. And perhaps for a novice it’s even better to just buy low quality resistors and destroy those instead of more expensive elements.Keep in mind, however, that resistors are not just resistances. Keeping resistance within tolerance limits is a no brainer. What you buy in a good quality product is many more crucial parameters. Voltage rating, power rating, good and predictable aging characteristics, reliability in a range of working conditions and environments to start with. Cheap, no-name imports have none of those specified and they are the hard part. So while using them, remember that they shouldn’t be used in line voltage circuits, where higher power may occur and the device works unattended, where leads may corrode or their anodic index is relevant etc.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 03, 2025, 08:21:01 pm
content: Most of what you just described are second-order effects when it comes to the lowly resistor.At this point in my explorations, I'm mostly in the first-order realm. If the resistors are even close to their supposed 1% tolerances, I'll be happy.And with more than 1,300 resistors about to land in my mailbox, I think I'll be set for a while; there won't be a second order for quite some time. (I already have a pretty good collection of decent-quality 5% resistors.)

author: watchmaker
author_rank: Unknown
timestamp: January 04, 2025, 03:51:20 pm
content: I buy my resistors from Ali and have no issues with them being out of tolerance. In fact, as measured by my Shannons, I get very little variation in values.I was curious about the comment about metal film so I scraped the coating off resistors from two different suppliers.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 04, 2025, 10:17:44 pm
content: The resistor pack came today.Looks good, very neatly packed, each strip hand-labeled with the resistance value.Leads are fine, not too thin.One thing threw me, which is that these parts use the 5-color code which I've never encountered before. (Is that an Asian/European thing?) So I'll have to learn to use that system. They included a helpful color-code card.Measured resistance indeed seems to be well within 1% (using an ordinary DMM).I'm happy.

author: themadhippy
author_rank: Super Contributor
timestamp: January 04, 2025, 10:34:05 pm
content: Quotedont think so,more out of necessity,hows ya gonna show 2.43K 1% with only 3 or 4 bands

author: Haenk
author_rank: Super Contributor
timestamp: January 05, 2025, 09:21:48 am
content: Quote from: golden_labels on January 03, 2025, 11:36:53 amI'd say that is more like a "pro" issue, you don't want to mess up customer qualified assemblies.But if you just want a quick DIY hack or replace your 20% carbon resistors, there is no reason not to use these.However - metal 1% resistors became so cheap, there is no reason not to stock a good set of commonly used ones. If you ever order from Digikey/Mouser/LCSC etc. - throw in 100pcs. of a certain value, that's only 2 USD or so. YAGEO has cheap 1% 50ppm 1/4W ones. Great deal, IMHO.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 05, 2025, 09:28:10 pm
content: My new 1% resistors are all sorted out and stored in a box I made, by base value separated by 1/3-tab cut dividers made from cover stock:That gave me 24 divisions, instead of the much greater number of individual values in this assortment.Now I just need to figure out how to store all the loose resistors I'll have in the future from breadboarding, etc. I could mix them into the "general population" I already have of 5% ones, but that'll be a problem, as those are all 4-color coded while these new ones are 5-color.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 05, 2025, 09:35:35 pm
content: Here's my regular resistor tray I made several years ago, with a thick cardboard base and chipboard dividers glued to it, spray-painted:Very sturdy and useful.Unfortunately, it only has slots for the E12 series. So maybe I need to make another one for my new treasure trove of E24 values.

author: Zero999
author_rank: Super Contributor
timestamp: January 05, 2025, 09:50:06 pm
content: Here's how I keep my resistors. Unfortunately, I've been unable to find more of those cases, because I want to adopt a similar system for small capacitors.

author: Analog Kid
author_rank: Super Contributor
timestamp: January 05, 2025, 09:55:18 pm
content: Nice system.

author: golden_labels
author_rank: Super Contributor
timestamp: January 06, 2025, 03:21:45 pm
content: Quote from: Analog Kid on January 03, 2025, 08:21:01 pmQuote from: Haenk on January 05, 2025, 09:21:48 amYes, as I said in the second paragraph: depends on the perspective and uses. But it’s important to realize the limitation exists and when one enters that other realm.Also, AnalogKid, very elegant storage!