And you think it's cold where you live
http://www.privateline.com/archive/minilinkericsson.jpg
(internal link to a larger picture (164K)
Click above to view this fine Ericsson photograph. (164K) It's from The Ericsson Chronicle by Merurling and Jeans. The photographer is not credited. The Chronicle is perhaps the best illustrated telephone history, a landmark in corporate biography design. 'Cmon, they're Swedish, they're going to produce something stylish. :-) Nearly 500 pages. I think I paid thirty dollars for it used but it was in great condition. You'll delight any telephone enthusiast this holiday season with a copy.
Stepper stumblings
I'm still trying to explain stepper operation, at least with the limited time I have right now. This ties in to Stephen Crowsen's comments on steppers here (internal link). How about relating the operating to a robot, with the selectors and brushes and contacts being its arms and fingers? Is that a warm and fuzzy enough comparison? Hmm. The subject needs much more pondering:
The difficult thing to imagine, at least for me, is that in a Strowger switch we first set up a mechanical path for a call to travel on. I suppose that applies to a cord switchboard as well. We take the cord and plug it into a jack. We have to make a mechanical connection before we connect electricaly. And with an electrical connection comes the call. A Strowger switch arranges a physical path by placing different mechanical devices, brushes, selectors, and so on, in contact with each other. This allows a complete electrical path. That arrangement is held in place by the switch until the call is disconnected and all of the pieces reset themselves.
Techs trying to trace a call are looking for the physical representation of the call path on the switch. While ignoring all the other calls being placed at the time. There's an exact point in the switch where the "3" and the "7" and the "4" and all the other numbers are connected. By looking at those they can determine the caller's number. But as the writer points out, without memory, the switch will extinguish those points of connection as soon as the call drops. Hmm.
What I'd really like to do is to go to the Roseville Telephone Museum and videotape their demo stepper. Then slow down the tape and make it into a QuickTime .mov file. Then, perhaps, people could see what's happening. Too much to do.