As more over-the-air viewers switch from analog to DTV, some station engineers are finding that DTV transmission requires quite a different skill set from analog transmission. Transmitter performance is defined by error vector magnitude or signal-to-noise ratio and shoulder levels. Linearity correction is done in software rather than by tweaking potentiometers while looking at a waveform monitor or vectorscope. Even a perfectly transmitted signal can fail on some DTVs or converter boxes if the PSIP information transmitted with the program streams isn't correct.
Broadcast engineers wanting to learn more about 8-VSB modulation and how to recognize deficiencies in the transmitted signal should consider taking the SBE On-line University 8-VSB Course written by Doug Garlinger, CPBE, 8VSB, CBNT and a Fellow in the Society of Broadcast Engineers (SBE).
While the focus of the course is RF transmission and the process employed to modulate the 19.39 Mbps ATSC transport stream onto RF, it will also touch briefly on video compression, picture formats, Active Format Description (AFD), PSIP and Dolby AC-3 audio.
The cost of the course is $100 for SBE members or $125 for non-members.
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