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IBM relay cabinets

spclock

Registered User
Aug 13, 2018
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Philadelphia, PA
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While I was posting some other stuff, I figured someone may be interested in pic's of several IBM relay cabinets I recently picked up. There is one 601-9 cabinet and 3 604-9 cabinets. These all came out of the same installation that dated from about 1950. (and are surprisingly heavy) The papers glued to the inside of the lids are schematics

601-9604-9.jpg 604-9a.jpg relay1.jpg relay2.jpg
 
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spclock

Registered User
Aug 13, 2018
14
14
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59
Philadelphia, PA
Country
I'll try and get some good images of the schematics that are glued to the lids and post them just FYI. I plan on eventually restoring the 601-9 cabinet and use it with the Navy clock instead of the power supply/relay setup I built. Unfortunately the contractor that removed this stuff was less than gentle .....,
It looks like the 601-9 cabinet powered the clock and each of the 604-9 cabinets powered a bank of slave clocks..
 
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Toughtool

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Aug 12, 2016
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Yeah, most transformers and relay contacts were only rated at 2 amps. They did have an 8 amp transformer and relays with higher contact ratings too. The bridge rectifiers was another limiting factor. The standard Copper Oxide rectifier was rated at 24 volts, 2 amps intermittent, but only 0.5 amps continuous. The newer Selenium rectifier was better, at 24 volts , 3.5 amps intermittent, but only 1 amp continuous. I think IBM started using stud mounted Silicon diodes in the early 1950's so these helped a lot I think.

So if there were a whole lot of seconderies, program devices, Bell, horns, and other devices, they would have multiple cabinets in order to extend the system.

I think you need to use the one on the left for your cabinet. It has the Run/Advance switch in it so it is probably the primary cabinet.
 
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Toughtool

Newbie
Aug 12, 2016
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Panama City, FL
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SP,
I found this paper some time ago on IBM's Clock Corner web site and just got around to reading it. I think this is a must read for anyone who has an IBM master clock or wants information about IBM's master clocks. Tell me what you think. Joe




Oops, On edit, I seem to have gotten tripped up. The IBM Document I am trying to reference is here:

https://www.ibm.com/ibm/history/exhibits/cc/pdf/cc_2407MLN2.pdf

I had searched on "2407MLN1 and this link to 2407MLN2 popped up. Still don't know why. Joe
 
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