Forwarded message:
Date: Sat, 2 Mar 1996 23:24:04 -0500 Subject: Re: RNG method
- Use a microphone on your sound card and locate it close to the computer fan.
It's been thought of before, along with scraping the microphone against the desk. I've been told this works best when first turning the gain up on the soundcard and setting it for stereo input.
If you use the fan remember in your power supply remember that many of them run directly off the 120 VAC. As a consequence the sound it makes will have a strong 60Hz componant. If you are using a DC bearing fan then there will be a componant in the noise related to the number of balls in the bearing. DC bearingless fans should provide the best white noise provided the bushings are not worn. Once they wear you will be a harmonic related to shaft diameter, shaft length, and the gap between main shaft and bushing.