Centraltryckeriet
Stockholm 1906
by Lars Aronsson in November 1997
This handbook shows the telephone and switchboard models in use by the Swedish national telecom in 1906, at the time named Kungliga Telegrafverket (the Royal Telegraph Administration). Telegrafverket's network carried the trademark Rikstelefon, seen in some of the photographs, and had competition from Allmänna Telefon, a private company. At the turn of the century, Sweden had more installed telephone lines per 1000 inhabitants than any other country in the world. (In the 1880s Stockholm had more telephone lines than any other city in the world, regardless of population.)
Copies of this book can be found in the Royal Library in Stockholm.
The year of issue (1906) is part of the
title, but it does not seem to be a periodical. The book has 282
pages, including an alphabetic index at the end. It is a quarto with
soft leather imitation cover. No author, illustrator, or photographer
is named. The book is no longer covered by copyright.
Because the amount of text is so small, a keyboard was used instead of OCR. All images were originally scanned in 300 dpi on a Hewlett-Packard Scanjet 4c scanner using the Deskscan software with settings "sharp color photo" (i.e. 256 colors) and a gamma correction factor of 1.8. Brightness and contrast were set automatically. Images were saved in JPEG format with a 70 % quality setting. These are the large images that you get when you click on an inline image. The inline images are scaled down to 1/8 size, corresponding to 38 dpi. On a normal computer screen, featuring 75 dpi, this means the inline images appear at half their size on paper, but the large images appear four times larger than on paper. The size of the inline images was chosen so to speed image load time for readers who use a modem to access this electronic edition. The size of the large images was chosen so to show all details of the circuit diagrams, and allow (on-paper) publishing quality of the photos.
The electronic edition has one HTML file for each telephone model, typically including one black-and-white photograph and one black-and-red circuit diagram. The yellowish background on all images shows the aging of the paper at the time of scanning. The above table of contents and glossary are not part of the printed copy. The numbers in the file names for HTML files and images indicate page numbers in the copy.
This electronic edition is under construction. So far, the first half of the book is covered (pp. 1-144). Not all large images are in place yet. Some links to pages beyond 144 are broken.
| Swedish abbreviation | Expansion, English explanation |
|---|---|
| telefonapparat | telephone |
| fälttelefon | field telephone (used by a repairman or by the military) |
| reseinduktor | mobile alternator |
| mikrotelefonväxel | handset switch |
| anknytningsväxel | branch switch |
| telefonväxel | telephone switch |
| ändst. | ändstation, end station, terminal equipment |
| mellanst. | mellanstation, intermediate station / equipment |
| Tbm, Ebm, Tvm, Tvh, etc. | These codes are not fully understood by the creator of this electronic edition, but a qualified guess is that the first letter indicates the manufacturer (T = Telegrafverket, E = Ericsson), the middle letter indicates the kind of mount (v = vägg = wallmounted, b = bord = table model, g = golv = floor model, s = stolpe = polemounted), and the last letter indicates the kind of handset (m = mikrotelefon = combined handset, h = hörtelefon = separate earphone). |
| med ab. | med automatisk beställning, with automatic ordering, i.e. the telephone has a dial of some kind. None of the telephones seem to have a rotary pulse dial. |
| dl. | dubbelledare, two-wire, 2-W |
| ledningsschema | circuit diagram, connection diagram (UK), schematic (US) |
