Harris Corp. used the final day of the National Association of Broadcasters annual trade show yesterday to announce that TV Azteca S.A. de C.V. signed a purchase agreement with Harris’ Broadcast Communications Division for digital television transmitters and high-definition encoding equipment for high-definition television (HDTV). The new equipment will allow for HDTV transmission in Mexico City, Guadalajara and Monterrey by the third quarter of this year. Phase two of the national rollout will bring HDTV services to six more cities in the first half of 2006.