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Beginners / Re: Checking for noise in resistors
« Last post by CatalinaWOW on Today at 05:48:25 pm »I think most of you are getting me wrong. I know about replacing the resistors for better ones, I already said that as well as I said that I'm just courious about the possibility to have a noise testing circuit. I'm sure there should be some designs out there. I'm aware of an old Heatkit tube signal tracer that can perform noise testing in components but such gear is almost impossible to get here in Europe, at least at a reasonable price.
Anyone know of some noise testing circuits out there? I'm sure there must be some around...
I haven't thought it all through, but I strongly believe you can accomplish what you want using the sound input of your computer. This should offer adequate signal to noise for the measurement but is uncalibrated. You can use FOSS software like Audacity to capture the data, or there are other open source programs more directly engineering oriented. Calibration could be achieved by measuring a good film resistor and using the the calculated Boltzman noise to scale the measurement. Read the Wikipedia article on Johnson-Nyquist noise for a quick run through of the calculation.