Bad resistors
in [Design]
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From: Jan Panteltje on 23 Jun 2010 06:18 On a sunny day (Wed, 23 Jun 2010 19:28:15 +1000) it happened Sylvia Else <sylvia(a)not.here.invalid> wrote in <88e2dfF7mgU3(a)mid.individual.net>: >On 23/06/2010 9:54 AM, DrParnassus wrote: >> On Tue, 22 Jun 2010 21:51:47 GMT, Jan Panteltje >> <pNaonStpealmtje(a)yahoo.com> wrote: >> >>> Got 10 resistors on tape marked 2M7. >>> Used one, circuit did not work right. >>> Took some testing ... before I measured the resistors. >>> Of the 10 several are 620 k and not 2M7. >>> Bought from www.voti.nl, so beware. >>> All are marked with the right color code for 2M7. >>> >>> New to me :-) >> >> A normal handheld DVM barely measures 1MOhm correctly so anything up >> there and over will not likely be easily measured with cheap handhelds. > >Still, you'd expect it to give the same wrong reading for the same >resistances. > >Sylvia. Exactly, and teh righ treading for correct ones. And 620 k is not even in that E series, it is 560k 680k. Maybe I can sell these on Ebay for a minimum of 1000$ to somebody, just like rare stamps? Any takers at 1000$?
From: Jan Panteltje on 23 Jun 2010 06:27 On a sunny day (Tue, 22 Jun 2010 18:43:30 -0700) it happened DrParnassus <DrParnassus(a)hereforlongtime.org> wrote in <9ep226t4osrqe89ifik2cburat2okc2aqd(a)4ax.com>: > And no, there is absolutely no way to guarantee the accuracy of the >reading ever, under any circumstance at that end of the range, past >1Mohm. even finger oils on the part that you DID just touch, makes a >difference. And yeas, I know that you are too stupid to have thought >about that aspect. John Larkin posted photo and diagram of a device to do just that here a few days ago? Why do you not stop arguing and get a basic electronics education? Building some circuits could help too.
From: Jan Panteltje on 23 Jun 2010 06:37 On a sunny day (23 Jun 2010 01:11:40 GMT) it happened Jay Ts <bitbucket(a)example.com> wrote in <gbdUn.533274$s21.30908(a)unlimited.newshosting.com>: >Jan Panteltje wrote: >> Got 10 resistors on tape marked 2M7. >> Used one, circuit did not work right. Took some testing ... before I >> measured the resistors. Of the 10 several are 620 k and not 2M7. Bought >> from www.voti.nl, so beware. >> All are marked with the right color code for 2M7. >> >> New to me :-) > >I will assume you have a decent meter and know how to use it. > >The web store looks like a tiny business, and you seem to >be complaining that you bought electronic components from >a guy who explained on his site that he is a software engineer, >and now you are not happy with your results. > >Before posting bad words about him publicly, he deserves to hear >from you and have an opportunity to correct the problem. Try >to resolve the problem first, before posting to the world. > >Aside from that, I've heard many stories of reject electronic >parts being resold by unethical businesses. Because of that, I >always buy parts from large, well-known companies (e.g., Mouser >and Digi-Key in the USA). Even they are not absolutely 100% perfect. > >Jay Ts I already had some 'correspondence' with them on other failing material. they are of my list as supplier. I had these in stock, hardly ever use those high values. I normally order from conrad.nl. I see it as my right to point out my experiences with things bought. You must be aware that the damage is not just a few cents for a resistor, but also the time it takes to trace the problem. Nobody is gona send 10 resistors back. I am just doing a public service pointing out the bad. F*ck any company that disagrees with that, if they sue me I have these as proof, unless somebody actually bust them at the 1000$ I ask as starting bid :-)
From: Jan Panteltje on 23 Jun 2010 06:38 On a sunny day (Tue, 22 Jun 2010 21:52:53 -0400) it happened Spehro Pefhany <speffSNIP(a)interlogDOTyou.knowwhat> wrote in <77q226to4fms4mdbulnv90dp4rki119h3q(a)4ax.com>: >On Tue, 22 Jun 2010 21:51:47 GMT, the renowned Jan Panteltje ><pNaonStpealmtje(a)yahoo.com> wrote: > >>Got 10 resistors on tape marked 2M7. >>Used one, circuit did not work right. >>Took some testing ... before I measured the resistors. >>Of the 10 several are 620 k and not 2M7. >>Bought from www.voti.nl, so beware. >>All are marked with the right color code for 2M7. >> >>New to me :-) > >Vhat is Wouter up to? Dunno.
From: Jan Panteltje on 23 Jun 2010 06:39
On a sunny day (Wed, 23 Jun 2010 15:00:49 +1000) it happened "Phil Allison" <phil_a(a)tpg.com.au> wrote in <88dioeFindU1(a)mid.individual.net>: > >"Jan Panteltje" >> Got 10 resistors on tape marked 2M7. >> Used one, circuit did not work right. >> Took some testing ... before I measured the resistors. >> Of the 10 several are 620 k and not 2M7. >> Bought from www.voti.nl, so beware. >> All are marked with the right color code for 2M7. >> >> New to me :-) > > >** Though pretty rare, I have come across wrongly marked resistors in a >piece of commercial equipment !! > >Dozens of resistors colour coded as 3.3kohms were in fact 4.7 kohms. > >The correct value WAS 4.7 kohms - so the equipment maker knew about the >wrong coding !! > > >.... Phil Yes I can understand that. But 2M7 -> 620k is not even in that E series (560k 680k 820 k). |