https://td-2.org/ 2026-06-13T18:55:53+00:00 https://td-2.org/ https://td-2.org/_media/wiki/logo.png 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" /> text/html 2026-05-28T01:54:42+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atelephone_communications_systems_vol_4_1970.pdf&ns=about&rev=1779933282&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="telephone_communications_systems_vol_4_1970.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-28T01:48:45+00:00 Michael Victor (s3200xl@undisclosed.example.com) https://td-2.org/?image=about%3Atelephone_communications_systems_vol_5_1970.pdf&ns=about&rev=1779932925&do=media <img src="https://td-2.org/lib/images/fileicons/svg/pdf.svg" alt="telephone_communications_systems_vol_5_1970.pdf" loading="lazy" width="500" height="500" /> text/html 2026-05-14T01:30:48+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/?image=passive_repeaters%3Amicroflect.kml&ns=passive_repeaters&rev=1778722248&do=media <img src="https://td-2.org/lib/images/fileicons/svg/file.svg" alt="microflect.kml" loading="lazy" width="500" height="500" /> text/html 2026-05-14T01:30:14+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/?image=passive_repeaters%3Amicroflect.kmz&ns=passive_repeaters&rev=1778722214&do=media <img src="https://td-2.org/lib/images/fileicons/svg/file.svg" alt="microflect.kmz" loading="lazy" width="500" height="500" /> text/html 2026-05-14T01:30:03+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/passive_repeaters?rev=1778722203 Passive Repeaters Passive microwave repeaters, of the panel style made by Microflect, are well covered in this article. The below map shows reflector-type passive repeaters that are still physically present, although many are no longer in service. (you can [download this KML file]) text/html 2026-05-14T01:26:16+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/misc?rev=1778721976 Miscellaneous 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 rather than microwave sites, and located in more developed areas. The tower designs may have simply been to reduce public opposition on aesthetic grounds, but perhaps there is more to it. text/html 2026-05-11T18:48:44+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/facilities/microwave/oak_hill?rev=1778525324 Oak Hill Microwave Station Oak Hill is a distinctive microwave site located on Communications Hill in San Jose, California. Many will recognize Oak Hill for the unusual concrete tower, which sits above a partially underground building. Much about the history of Oak Hill is obscure, including the reason for the unusual construction. Functionally, Oak Hill was a microwave station for connectivity to the San Jose CO and likely also exchanged microwave traffic with an L-carrier cable that runs nort… text/html 2026-05-10T20:20:13+00:00 J. B. Crawford (jesse@undisclosed.example.com) https://td-2.org/sidebar?rev=1778444413 * Facilities * Long-Distance Carriers * Long-Distance Routes * Collections * Maps * Emergency Alerting Systems * Military Communications Systems * Miscellaneous * About TD-2