https://td-2.org/ 2026-07-28T22:18:26+00:00 https://td-2.org/ https://td-2.org/_media/wiki/logo.png text/html 2026-07-06T19:46:45+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/utility/bpa?rev=1783367205 Bonneville Power Administration Microwave Network The BPA's historic microwave communications network is well documented in a historical inventory, and was covered in Computers Are Bad. The first form of the network, built in the very late 1940s and early 1950s, used 23/24 channel ~2 GHz equipment from Federal Telecommunication Laboratories/ITT. During the 1960s many links were upgraded to 600-channel equipment (in 72-channel banks) over 8 text/html 2026-07-06T19:28:58+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/?image=utility%3Abpa%3Abpa_map.kml&ns=utility%3Abpa&rev=1783366138&do=media <img src="https://td-2.org/lib/images/fileicons/svg/file.svg" alt="bpa_map.kml" loading="lazy" width="500" height="500" /> text/html 2026-07-06T19:22:52+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/misc?rev=1783365772 Miscellaneous Utility Networks To support their long-distance transmission infrastructure, electrical utilities often operate large microwave networks. * Bonneville Power Administration Microwave Network Interesting Equipment * Passive Repeaters Interesting Concrete Towers Most AT&T microwave sites use nearly identical concrete columns (earlier sites) or steel lattice towers (later sites), but a few have architecturally interesting concrete towers. Many of these are tandem offices rat… text/html 2026-06-19T23:09:59+00:00 Anonymous (anonymous@undisclosed.example.com) https://td-2.org/about/contribute?rev=1781910599 Contributor's Guide The goal of TD-2 is to become an open wiki with many contributors. To avoid problems with spam and abuse, though, account registration isn't open. If you're interested in contributing, please contact info@td-2.org to request an account. text/html 2026-06-19T01:13:37+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/resources?rev=1781831617 Resources This page aims to serve as an index of useful resources for researching telecom history. Telecom Archive telecomarchive.com has an expansive index of historic Bell System documents, including Bell System Practices (BSP) and Bell Laboratories Review (BLR), Schematic Drawings (SD), and more. text/html 2026-06-18T19:52:05+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/sidebar?rev=1781812325 * Facilities * Long-Distance Carriers * Long-Distance Routes * Resources * Maps * Emergency Alerting Systems * Military Communications Systems * Miscellaneous * About TD-2 text/html 2026-06-18T19:51:47+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/collections?rev=1781812307 text/html 2026-06-17T02:17:52+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/maps/start?rev=1781662672 Maps Here you will find a collection of historic maps of telephone and telecommunications lines. They are collected from various sources, many of which were already secondhand collections---so a source is noted when possible, but it's hard to be 100% certain where these all came from. The maps are presented by the year they were created and the name shown on the map, when possible. The M# is a text/html 2026-05-28T02:08:55+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Abtl_transmission_systems_for_communications_4ed_1971.pdf&ns=about&rev=1779934135&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="btl_transmission_systems_for_communications_4ed_1971.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:08:15+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Abtl_transmission_systems_for_communications_vol_2_1959.pdf&ns=about&rev=1779934095&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="btl_transmission_systems_for_communications_vol_2_1959.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:07:00+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Abtl_transmission_systems_for_communications_vol_1_1959.pdf&ns=about&rev=1779934020&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="btl_transmission_systems_for_communications_vol_1_1959.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:05:10+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Aengineering_and_operations_in_the_bell_system_2ed_1984.pdf&ns=about&rev=1779933910&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="engineering_and_operations_in_the_bell_system_2ed_1984.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:04:34+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3A1977_engineering_in_the_the_bell_system_1st_edition.pdf&ns=about&rev=1779933874&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="1977_engineering_in_the_the_bell_system_1st_edition.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:03:55+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Anotes_on_distance_dialing_1968_.pdf&ns=about&rev=1779933835&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="notes_on_distance_dialing_1968_.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:03:28+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Awestern_electric_1980_notes_on_the_network.pdf&ns=about&rev=1779933808&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="western_electric_1980_notes_on_the_network.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:02:33+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atransmission_principles_1966.pdf&ns=about&rev=1779933753&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="transmission_principles_1966.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T02:01:25+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Acarrier_systems_1966_western_electric.pdf&ns=about&rev=1779933685&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="carrier_systems_1966_western_electric.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T01:59:49+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atelephone_communications_systems_vol_1_1970.pdf&ns=about&rev=1779933589&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="telephone_communications_systems_vol_1_1970.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T01:59:17+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atelephone_communications_systems_vol_2_1970.pdf&ns=about&rev=1779933557&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="telephone_communications_systems_vol_2_1970.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T01:58:36+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atelephone_communications_systems_vol_3_1970.pdf&ns=about&rev=1779933516&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="telephone_communications_systems_vol_3_1970.pdf" loading="lazy" width="500" height="500" />