20
by eliya_Archive
What's the consensus on tape storage near power cords?I have my tapes stored on a shelf, and a couple shelves above it I have a few pieces of equipemnt that feed off of AC.Intuitively, it seems to me like it shouldn't be a problem because tape machines work off of 120VAC, and a lot of times the AC inlet is only a few inches from the tape path and turntables. However, when I try and think about the magnetic field that the AC current generate, I get a little stuck.Here's what I get for B in open air, assuming that there's 10A (an exaggeration) flowing through the cord and that the cord is 15cm from the tapes.B = 1.257x10^(-6) * [10/(2*pi*0.15)] = 0.0000133 T.To get to Webers we multiply by area, and let's say the area that the flux from the cord will interact with the tape is 0.015m^2 (2 tape times 12). That givesB * Area = 0.000000199 Wb = 199nWb.But fluxivity is measured in nWb/m, and honestly I'm not sure how to bridge the two, but I'm thinking that if a 2 by 12 strip of tape is exposed to 199nWb of flux, then putting it in terms of nWb/m it is 663.3nWb/m, which is quite hot. The good news (I think) is that there's no bias applied to the tape, so that makes it harder for the AC to print on the tape. But I don't know how hard.I'm also not sure how much flux would erase a tape, but would that be enough?I bet someone worked out all this stuff before, but I couldn't find anything like that online.