> -----Original Message----- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of ben > Sent: 31 August 2015 01:43 > To: cctalk@classiccmp.org > Subject: Re: IBM 1620 > > On 8/30/2015 6:32 PM, Tothwolf wrote: > > > On page 5, they describe 0.0031" 40 AWG magnet wire being reduced to > > 0.002" after soldering with 60/40 tin-lead solder. That 0.0011" > > reduction is basically 1/3 of the diameter of the wire. This explains > > the failures of the enamel wires in CHM's IBM 1620. > > > > Copper erosion from tin is something I'd never really given a lot of > > thought to, but it will certainly be something I keep in mind from now on. > > > But is that the case? Would not heat induced failure be the real case here as I > suspect that a amp or two of current is flowing that now very thin thread of > wire? Digging though the doc's and a little calculation clear this up. > Ben. > >
I seem to remember that 1620 core runs warm, and you have to wait for it to get warm before the machine comes on-line ... see last paragraph http://www.angelfire.com/oh3/ebjoew/IBM_1620_Core_Memory.html Dave Wade
