Wednesday Febuary 23, 2011

Attendees: Ron Williams, Bob Erickson, Robert Garner, George Ahearn, Stan Paddock, Bill Flora, Frank King,  Don Luke, Douglas Martin, Bill Newman, Joe Preston,  Ron Crane

Frank King heard a noise from the IBM 1403 attached to the Connecticut system.

After removing the main cover and other parts surrounding the top blower motor

 , he decided the noise was coming from the IBM 729 tape drive behind the IBM 1403.

Frank then put the 1403 back together and started looking for the noise in the IBM 729 tape drive.

Don Luke continued his efforts to build a course outline to teach the IBM 401 internals.

Ron Crane continued his evaluation for the power going into the German 308 volt 50HZ system.

The term Power Factor defines if the current waveform peak occurs at the same time as the voltage peak. The picture below is of one of the three legs going into the German System.

While this leg looks good, the other two legs show a considerable shift in the power factor.

Ron had brought in some small capacitors which he hooked to the first leg. The sum of theses capacitors (25Uf) cut the problem in half. With the installation of three capacitors of the correct size, the load to the power converter can be reduced by at least a kilowatt. This excess power has to be removed from the room via at least another kilowatt worth of Air Conditioning.

(to be continued.)

 

Robert Garner and George Ahearn discuss some historical publishing regarding early computers.

Ron Williams and Don Luke discuss the old times when the IBM 1401 was considered "State of the Art".

Ron Williams, Bob Erickson and Bill Flora look for a small missing "C" clip for the Connecticut 1402.

Bill Newman, Ron Crane, Bob Erickson and George Ahearn discuss the way they think an old IBM Model "B" transmitting typewriter works.

Stan Paddock