IBM 1620

ben bfranchuk at
Sun Aug 30 19:43:02 CDT 2015

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.

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