Common Language Location Identifier (CLLI): unknown
Geolocation (GL) code: unknown
Address: 23520 West Grand Ave., Lake Zurich, IL
Latitude: N42-11-17 (42.18806)
Longitude: W88-05-32 (-88.09222)
Elevation: 894 ft. (272 M)
Location: unknown
Active AT&T Callsigns: none
Canceled AT&T Callsigns: KSA74
Lake Zurich's physical facilities consist of a cylindrical concrete "silo" tower and a 280 ft. self-supporting steel-lattice tower.
The Lake Zurich station's concrete tower, along with identical towers at Spring Grove, IL and Prospect, WI, was constructed during the summer of 1948 to provide a one way television route from Chicago to Milwaukee.
The tower was constructed by the fixed form method and has the shape of a circular, tapered silo with an overall height of 101 feet to the top platform. A steel stairway was built alongside the silo to provide access to floors 2 thru 5, an additional steel stairway was located within the silo leading from floor 5 to floor 6.
The sixth floor of each tower housed TE-1 microwave equipment, a short haul radio relay system utilizing reflex klystrons. Each tower had a pair of KS-5706 metal lens antennas installed on the lower deck, one facing each direction of the route, these antennas were of a different design than the delay lens antennas used in later installations. This same type of antenna was used a year earlier for AT&T's first microwave installation running from New York to Boston.
AT&T only built six towers of this design before switching to the more familiar square, straight sided concrete towers.
The tower was used as a television relay until 1953, at which time a parallel route using TD-2 equipment was built somewhat farther west. The new route ran from Chicago to Minneapolis, with a branching point at Palmyra, WI connecting to Prospect and on to Milwaukee.
The type A steel lattice tower was constructed in 1953. Four KS-5759 list 2 delay lens antennas were installed on the new tower, along with TD-2 equipment in the upper section of the concrete tower. A bridge was constructed to support the waveguides between the two structures. The original route through Spring Grove was decommissioned around this time.
When AT&T converted its transmission network to fiber optics, Lake Zurich was no longer needed and was shut down. In 1989 AT&T sold the station to Ameritech Cellular, which installed a cellular antenna array on the tower. A few years later Ameritech/SBC sold this site and a number of others to Crown Castle International, which leases space on the tower to cellular telephone companies and other wireless communications providers. Crown Castle has produced a site data page describing the facility.
 Courtesy of J.P. Maurer |
 Courtesy of J.P. Maurer |
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From the April 1949 Bell Laboratories RecordCourtesy of Terry Michaels |
From the January 1949 Midwest EngineerCourtesy of Terry Michaels |
From the September-October 1958 Wisconsin Telephone NewsCourtesy of Terry Michaels |
Updated on May 11, 2003 at 10:50 by Albert LaFrance