WRAL-HD DTV Complete Field Test Report

Abstract

WRAL-HD conducted one of the nation's first digital television (DTV) field tests. This report will explain the testing methods, results, and analysis of this test, with the final section devoted to comparisons with measured NTSC reception. The testing consisted of four phases that explored different aspects of the new transmission service. In the different areas of testing, the results showed that outdoor service availability of the 100-kW high-definition television (HDTV) service was 89.6% when measured to 65 miles. Also, a horizontally polarized transmitting antenna was compared to a circularly polarized transmitting antenna with no significant advantage or disadvantage found for either antenna to existing receive antennas. Testing was included from the inside of various residences and showed that the problems, which have always affected indoor NTSC reception, will need to be addressed with DTV. Finally, WRAL-HD's sidemounted DTV transmitting antenna was tested for pattern nulls and receiver white noise enhancement and showed that the tower does have an effect on the DTV transmission, but it is minimal and should not prevent the implementation of this type antenna. This report also contains some detailed comparisons between a 5000-kW NTSC signal and the DTV signal. With the NTSC signal enjoying not only a greater power but other transmission advantages as well, the outdoor service availability of the NTSC was 92.5% and for the DTV signal it was 91.8%. These comparisons were also evaluated for indoor reception. This report will detail these and other findings.