Apparatus and method are presented for measuring the transmitter and antenna system time delay (TAD) of the cadence sync at the input of a conventional 8 VSB data processing system until the emission of the segment sync of the corresponding data frame sync data segment. This includes sequentially conditioning a multi-bit input digital signal containing an initial cadence sync, inserting data patterns into the digital signal, inserting a known data pattern into the data frame at a known position of the data frame and receiving the cadence sync and the known pattern and measuring the time delay therebetween.