HDTV Overview Wayne Kube Kube Broadcast Consulting, Inc.

NTSC & DTV Comparison NTSC was fully analog Amplitude Modulation (with vestigial sideband) for visual content Upper sideband used for majority of picture information – not suppressed carrier Lower sideband – most of content removed, but some (vestige) left – thus VSB (Reason was high quality filtering had not been developed that early) Frequency Modulation for aural content 25 KHz deviation (FM broadcast is 75 KHz deviation) Stereo developed in 1980s (BTSC) Aural carrier typically 10% of visual carrier amplitude (average vs. peak) Most receivers used inter-carrier demodulation of the aural carrier – used the precise 4.5 MHz difference between visual and aural carriers. That required that there always be some amount of the visual carrier present, or the audio would buzz. ATSC is fully digital Amplitude Modulation for all content 8 levels of Amplitude Modulation – 8VSB Video, audio, PSIP, other data all multiplexed into one stream megabaud; gross bit rate of 32Mb/s; net bit rate of Mb/s Mb/s transmitted within one 6 MHz RF channel

NTSC & DTV Comparison 316 KW ERP 31.6 KW ERP

NTSC & DTV Comparison 55 KW ERP (average)

NTSC & DTV Comparison

KERA-TV Channel 13 Physical Ch 14, Virtual Ch 13

Physical Channels vs. Virtual Channels The RF channel may or may not be the same as the virtual channel Most stations kept their original analog channel number as their virtual channel for branding continuity This is because PSIP (Program and System Information Protocol) makes it irrelevant to the viewer DTV receivers will scan the channels and generate a table that associates virtual channels with physical channels

Studio End

Transmitter End

Dallas/Fort Worth DTV Stations StationVir. ChanRF. ChanFreqProgramsStreams KDTN KDFW KXAS , 5.22 WFAA , 8.2, 8.33 KTVT , KERA , KPFW-LD , 18.2, 18.3, KBOP-LD , 20.2, 20.3, KTXA , KUVN , 23.2, 23.3, K25FW KODF-LD , 26.2, 26.3, KDFI , 27.2, 27.33

StationVir. ChanRF. ChanFreqProgramsStreams KHPK-LD , 28.2, 28.3, KMPX KWDA-LD , 30.2, 30.3, 30.4, 30.5, 30.6,.30.7,.30.8, K31GL-LD , 31.2, 31.3, 31.4, KDAF , 33.2, KJJM-LD , 34.2, 34.3, 34.4, KXTX , KLEG-CD , 44.2, 44.3, KTXD , 47.2, 47.3, 47.4, KST , 49.2, KATA-CD , 50.2, 50.3, KHFD-LD , 51.2, 51.3, 51.4, 51.5, 51.6, 51.7, KFWD KAZD , 55.2, 55.3, 55.4, 55.5, 55.6, KDTX , 58.2, 58.3, 58.4, KPXD , 68.2, 68.3, 68.4, ( encrypted)4

Chan. 17 – Dielectric TFU-20EBT 47 ft long, 10,600 lbs

Transmission Details ERP – 1,000 KW Antenna Gain – 17.5 (12.43 dB) – Omnidirectional Antenna Input Power – kW Transmission Line – 1,500 ft of 8-3/16” rigid coax Loss in the transmission line – 1.21 dB – kW (75.7% efficiency) Transmitter Power Output – kW Would require a three IOT transmitter, each IOT at 30 kW rating, water cooled The IOT operates at about 25 kVDC, 3 amps Transmitter efficiency in the 30% range New solid state transmitters achieve >60% efficiency. 50 VDC, water cooled.

WFAA History WFAA Radio (AM) signed on June, 1922 (Working For All Alike) Moved to 570 KC (not KHz back then) in 1938 Shared 570 and 820 with WBAP until 1970 WFAA-FM started October WFAA-TV started as KBTV-TV in September, 1949 (Dumont network) A. H. Belo purchased KBTV from oilman Tom Potter for $575K in March, 1950 and changed the call letters to WFAA-TV. First VHF DTV station in the nation, and first DTV station in Texas – February 27, 1998 Analog shut-down June 12, , Belo sold all TV stations to Gannett. 2015, Gannett Broadcast changed its name to TEGNA.

January 4, 1987

Thanks for inviting me!