Tribune/WGN DTV field test

Abstract

Tribune Broadcasting Corporation, owner of 18 broadcast stations spread throughout the United States, including WGN-TV in Chicago, is dedicated to bringing DTV service to its viewers. On March 25, 1998, Tribune's WGN-TV became the first TV station to begin DTV field testing in Chicago, Illinois. The Advanced Television System Committee (ATSC) signal was successfully received first in the northwest suburb of Mount Prospect, and then subsequently received around the entire Chicago-land area during three weeks of testing. This marks the first time a DTV field test was performed using a transmitter site situated in a major city from atop a large building in the center of the city. Previous tests utilized a transmitter that was located outside the major city of coverage. This provided information about the various types of multipath that occurs when DTV signals bounce off large building structures close to the transmitter. Also of interest was the performance of DTV when transmitting through an existing RF NTSC system (HPA, coaxial feedline, and narrow-band antenna) using a side-mounted antenna from a lower height transmitter tower (compared to the Sears and Amoco buildings). This report describes the testing methods, data results, and analysis of this Chicago DTV field test. Two phases of testing were performed and completed: March 25-29, 1998, and May 13-23, 1998. Both outdoor and indoor testing were performed, the results of which are described.