cheap precision resistors?

[ralphd]

I'm looking for 10-20 precision resistors to make a current reference.  The cheapest 0.1% resistors I can find are around 35c ea.  While it is cheap in absolute terms, relative to 1% chip resistors, that's about 10x the cost.
Is that to be expected?

[ralphd]

Here's the ones I'm thinking of buying:
http://m.aliexpress.com/item/32336524608.html

[JuKu]

Yes, that is about right. 10x the precision, 10x the cost. :-)

[JacquesBBB]

Here's the ones I'm thinking of buying:
http://m.aliexpress.com/item/32336524608.html

I would not trust precision resistors from aliexpress unless you have very good garanties. Moreover, you will not pay more on a reputable provider as Mouser or others.

[ralphd]

Here's the ones I'm thinking of buying:
http://m.aliexpress.com/item/32336524608.html

I would not trust precision resistors from aliexpress unless you have very good garanties. Moreover, you will not pay more on a reputable provider as Mouser or others.

It's the shipping cost that makes Mouser & Newark too expensive.  Digi-key may still be an option if I have a reasonable size order, and if they still have $8 shipping to Candada.

[ralphd]

Here's the ones I'm thinking of buying:
http://m.aliexpress.com/item/32336524608.html

I would not trust precision resistors from aliexpress unless you have very good garanties. Moreover, you will not pay more on a reputable provider as Mouser or others.

It's the shipping cost that makes Mouser & Newark too expensive.  Digi-key may still be an option if I have a reasonable size order, and if they still have $8 shipping to Candada.

Where in Canada are you?  There are many large distributors in Canada [Future Electronics, etc.], and they can send via Canada post just like anyone else can.

East coast.  Last time I looked at Future Electronics, they didn't have transparent pricing.  I won't setup an account just to find out pricing.

[rs20]

Don't forget that the error in a 1% resistor can trivially be cancelled out in firmware (if applicable) or with a trimpot, whereas temperature coefficient is much harder to deal with. In many of the EEVBlog teardowns of multimeters etc, you see crucial, critical components with 1% or even 10% tolerances; but it turns out that have extraordinarily low drift and tempco for exactly this reason.

[ralphd]

Just checked FutureElectronics.  Their web site still sucks.  No mobile-enabled site, and when I type in a part in the search box and hit enter, nothing happens.

[ralphd]

Don't forget that the error in a 1% resistor can trivially be cancelled out in firmware (if applicable) or with a trimpot, whereas temperature coefficient is much harder to deal with. In many of the EEVBlog teardowns of multimeters etc, you see crucial, critical components with 1% or even 10% tolerances; but it turns out that have extraordinarily low drift and tempco for exactly this reason.

I don't have accurate calibration sources, so I need parts with good initial accuracy.  With a couple REF5050s and a bunch of tl431s, I hand picked a couple of the tl431s that should be within 0.05% of 2.50V.  Then with a 250 Ohm resistor I'll make a simple and cheap 10mA reference.
I also want the precision resistors to check the accuracy of my Colluck DMM.

[ralphd]

I was all set to get another Newark order a couple months ago until I saw the new shipping rates when I got to the checkout.

[JacquesBBB]

The way I proceed with Mouser to avoid shipping fee, is to fill a project list whenever I think I need some parts.
Then, when I  urgently need a specific part for a project, I just grab whatever I have in my backlist to
fill the gap up to 65 $.
You just have to be patient, but  I found that for many parts (electrolytic caps in particular), Mouser offers better deals
than ebay, and with reliable parts.
What I say about Mouser can of course be translated to any other big company.

[ralphd]

Hint: For those experimenters on a tight budget, a possible way to get access to all kinds of fantastic equipment is to take just one university class: "Electronics Lab"

Most Canadian university classes are > $500 per semester.  Even the cheapest community college courses are >$200.  On top of that, most courses require you to be admitted to a degree or diploma program.