Author Topic: Let's make some noise!  (Read 1807 times)

blackhole

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Let's make some noise!
« on: December 31, 2010, 04:28:21 AM »
All want no noise... let's be different, let's make noise!
White one, for measurements... let's say from 0.1Hz to 25MHz - OK, that's a little but too optimistic.
And it must run on batteries, one or two 9V. I like to use them for low noise PS.
Any ideas?

I think of using zener. Which one? 5.6V, 7.5V? Ordinary or special noise diodes, e.g. NoiseCom NC104 or NC202 - how to get those?!! I have no idea regarding their price.
Simple resistor or CSS to feed the zener to avoid 9V battery voltage drop? I am not sure about this. Moreover, I do not want to sneak to much of resistor/CSS 1/f noise in.
What current though the zener? I say you'll say try and measure :)

Has anyone measured zener noise spectra? Where is typical 1/f region? Noise bandwidth? Any suggestions?

After settling this down there is a need to amplify this noise... I think of:
fixed gain + variable LP RC filter + variable gain. The critical is first stage.
It should not contribute any 1/f. Around G=40dB, I guess. FET gain device (or IC).

All this are just my first ideas.

Cheers