Lake Zurich, IL

Common Language Location Identifier (CLLI): unknown
Geolocation (GL) code: unknown

Site Data

FCC Microwave License Data


Lake Zurich's physical facilities consist of a cylindrical concrete "silo" tower and a 280 ft. self-supporting steel-lattice tower.


Thanks to Terry Michaels for contributing this section

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.


Select an image to view a larger version

Courtesy of J.P. Maurer

Courtesy of J.P. Maurer

From the April 1949 Bell Laboratories Record
Courtesy of Terry Michaels

From the January 1949 Midwest Engineer
Courtesy of Terry Michaels

From the September-October 1958 Wisconsin Telephone News
Courtesy of Terry Michaels

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Updated on May 11, 2003 at 10:50 by Albert LaFrance