31 Aug
2015
31 Aug
'15
12:59 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of ben
Sent: 31 August 2015 01:43
To: cctalk at 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.
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