09-10-2019, 12:00 PM
(09-10-2019, 10:07 AM)Amie Wrote: Dad told me that when he was first interested in electronics and was building something that required say 2% components, he would (in ignorance) try to select values from a batch wider tolerance types, apart from other problems, he found that the values of 20% resistors for instance would be within 20% but outside 10%, he says probably because they were selected from production runs as 5%, 10%, 20%.
Yes - and as Jeffrey has already commented, this was done, and your Dad experienced it!
Another trick, which a capacitor manufacturer told me - they improved their process accuracy so they could guarantee the values of finished components to within 2%. But quite often the market didn't need that and was happy with 10%. So, instead of making 100nF capacitors actually AT 100nF, they would make then to 93nF (which would turn out to be 91 - 95nF) saving on materials, and sell them as 100nF +/- 10%. So it is exceedingly unlikely that you would find any actually measuring at 100nF, and even less likely that they would be above 100nF.
