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facilities:microwave:oak_hill [2026-05-10 17:10] – J. B. Crawfordfacilities:microwave:oak_hill [2026-05-10 21:22] (current) – J. B. Crawford
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 ====== Oak Hill Microwave Station ====== ====== 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 an underground building that is semi-hardened at most. Much about the history of Oak Hill is obscure, including the reason for the unusual construction. Functionally, Oak Hill was a microwave station and likely also exchanged microwave traffic with an L-carrier cable that runs north-south through California.+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 an underground building that is semi-hardened at most. 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 north-south through California.
  
-^ Built    | Late 1960s? |+^ Built    | 1972 |
 ^ Builder    | AT&T | ^ Builder    | AT&T |
 /* Suggested table rows: */ /* Suggested table rows: */
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 | San Jose | North | WLEL | | San Jose | North | WLEL |
  
-This list is probably incomplete and confusing, the routes seem to have changed over time. A [[https://groups.io/g/coldwarcomms/message/4739|mailing list post]] from Wayne M H also gives the following:+This list is probably incomplete and confusing, the routes seem to have changed over time. A [[https://groups.io/g/coldwarcomms/message/4739|mailing list post]] from Wayne M H also gives the following. I am not familiar with the maps referenced.
  
   The map I have that seems post-1979 shows Oak Hill with a MW path to   The map I have that seems post-1979 shows Oak Hill with a MW path to
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 The history of the Oak Hill site is not well documented, but LinearBob WA6WHT sent [[https://groups.io/g/coldwarcomms/message/23744?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2Coak+hill%2C20%2C2%2C20%2C53551270|an explanation]] to the ColdWarComms list that goes like this: AT&T originally intended to add floors to its downtown San Jose office (on Almaden Road) and mount microwave antennas there, but expansion of the San Jose Airport lead the FAA to prohibit the added height. Instead, AT&T selected the Communications Hill site, which was already known by that name due to a Santa Clara County emergency communications facility nearby. This became known as "Oak Hill" within AT&T, and the microwave facility served mostly as a "remote" radio site for the San Jose downtown office. The history of the Oak Hill site is not well documented, but LinearBob WA6WHT sent [[https://groups.io/g/coldwarcomms/message/23744?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2Coak+hill%2C20%2C2%2C20%2C53551270|an explanation]] to the ColdWarComms list that goes like this: AT&T originally intended to add floors to its downtown San Jose office (on Almaden Road) and mount microwave antennas there, but expansion of the San Jose Airport lead the FAA to prohibit the added height. Instead, AT&T selected the Communications Hill site, which was already known by that name due to a Santa Clara County emergency communications facility nearby. This became known as "Oak Hill" within AT&T, and the microwave facility served mostly as a "remote" radio site for the San Jose downtown office.
  
-Based on LinearBob's story, construction of Oak Hill would have been sometime in the late 1960s or 1970s. Indeed, historic aerial images bracket it between 1968 and 1980.+Based on LinearBob's story, construction of Oak Hill would have been sometime in the late 1960s or 1970s. Indeed, historic aerial images bracket it between 1968 and 1980, and a tangential mention in a San Jose planning document puts the date of construction at 1972.
  
 Microwave IF signals were conveyed between San Jose and Oak Hill over 4-5 miles of coaxial cable, allowing most of the mux equipment to stay at San Jose and perhaps explaining the relatively small floor area and power plant at Oak Hill. This was a system called "WLEL" or "Wireline Entrance Link," used for short-haul carriage of microwave supergroups. Microwave IF signals were conveyed between San Jose and Oak Hill over 4-5 miles of coaxial cable, allowing most of the mux equipment to stay at San Jose and perhaps explaining the relatively small floor area and power plant at Oak Hill. This was a system called "WLEL" or "Wireline Entrance Link," used for short-haul carriage of microwave supergroups.