The Government? The FBI has the most sophisticated software programs in the world for extracting conversations from background noise. Who are you, and what are you up to?
You won't harm the PC, IT is the source of the noise. One to two feet should be OK. I've never tried it, but aluminum foil may work to some extent. Not to worry, you will probably experience no problems, and at worst, you will get a little noise in your recordings. Many record successfully...
Shielding can consist of any conductive metal sheet that is connected to earth ground. Mu metal is best, but very expensive. Often used is bronze window screening. Be aware however unless the shielding completely surrounds the protected or offending device (A Faraday Cage) it is not...
Take a small tranistor radio and hold it near the PC (and the monitor) it will pick up the airborne switching noise up to about a foot away, Preamps and such are even more sensitive, Keep the PC and its monitor as far from your audio equipment as space allows, or use grounded shielding between...
Take a puff and blow it through a piece of white cloth. The residue You see is what's left over after your lungs get their share. Where do you suppose all that residue goes when exhaled into your room or in the proximity of your recording gear? Computers are even worse because they have fans to...
I meant to say inner tube not "tire."T he reel hub is close to the relaxed size of the resulting rubber band, so it should fit widthwise. If not, compensate when cutting.