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August Singing Wires is now available in the members login area.

Telephone Collectors International is an organization of telephone collectors, hobbyists and historians who are helping to preserve the history of the telecommunications industry through the collection of telephones and telephone related material. Our collections represent all aspects of the industry; from the very first wooden prototypes that started the industry to the technological marvels that made the automatic telephone exchange possible.

If any of this interests you, we invite you to join our organization. Look around and see what we have to offer. Thanks for stopping by!

Telephone Collectors International
3805 Spurr Circle
Brea, CA 92823
714-528-3561

Sample from the August 2014 Singing Wires
First Transcontinental Phone Call

On July 29, 1914, a test call was successfully put through from New York to San Francisco over the first transcontinental telephone line. It was a mere 38 years after the birth of the telephone on March 10, 1876, when the first message went over the only telephone line in the world - a line less than a hundred feet long.

There were many things that occurred prior to this time that made the call possible. One of the most important was, no doubt, when telegraphy came under the influence of Bell in 1914 when the company bought Lee deForest's patents on electronic amplification devices to extend the range of long distance telephone messages.

On January 25, 1915, the transcontinental telephone wires were given their first public demonstration, when the completion of the line was formally celebrated as part of the Panama-Pacific Exposition. Distinguished men in the offices of the Pacific Telephone Company in San Francisco conversed with......

For the rest of this story along with many others, access to our Bonus Pages which contain many more photos, online access to all back issues of Singing Wires from 1986 on and many other benefits, join our club. It's easy and it's not expensive.

Sample from the July 2014 Switchers' Quarterly
Trunking in the Ericsson AGF Switching System
By Chris Mattingly

The system is based on switches that can select one of 500 positions in two motions. Rows of phosphor bronze bars the diameter of pencil lead are arranged in straight rows (called a "frame") in a semi arc running up and down the equipment rack. The contact wipers are mounted as such that they can rotate around 90 degrees one to 25 positions then extend in to a row of bars one to 20 positions, for a total of 500 positions.

Each office can grow to a maximum of 10,000 lines. Twenty frames are needed on the selector to access the connector switches needed to access 10,000 lines. That leaves five frames for trunks to other offices or 10,000 line groups in the same office. In figure one, a diagram of the selector frames is shown. The wipers are idled on the left side of the frames and they rotate clockwise, or to the right. The first five positions are for access to trunks and the remaining 20 are for the connectors. Each rectangle on the diagram represents a frame, the set of bars needed for 20 positions, which are wired to switches downstream from there. The wipers stop at the desired position, under the control of the register. The switch then extends the wipers into the frame and stops on the first idle position to seize a switch in the downstream rack.

Figure two shows a simple diagram for a 500 block of lines. There would be 20 of these for a 10,000 line office. For an office this size.....

Our Journal for those interested in telephone switching systems, both old and modern. For the rest of this story and online access to all back issues, join our club and add the Switchers' Quarterly option for $5 a year more.

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