Wednesday, April 25, 2012

TV DXing in the Digital Age

In the 29 years I've been seriously DXing television, no adjustment has been as major as the transition here in the United States from analog to digital television three years ago. Many of us remember the "nightlight" operations by several TV stations of their analog signals broadcasting public service announcements on the conversion to digital for one month. In my home state, the stations that did this included KSDK 5 St. Louis, KRCG 13 Jefferson City, KYTV 3 Springfield and KMBC 9 Kansas City. Of course, KSDK now operates on UHF Channel 35, KYTV on UHF Channel 44 and KMBC on UHF Channel 29. KRCG remained on VHF, operating on Channel 12. Via E-skip, I pulled in such operations from WGBH Boston, WPBT Miami and KPRC-TV Houston (both on VHF Channel 2), as well as the TV stations run by the University of North Carolina.

It was well worth the money I paid for my first digital TV tuner, a Digital Stream HD3150. I bought it in 2005. I used this for DX for the first three years of my DXing digital TV signals. The tuner is now part of my entertainment system, but is still hooked to the same Radio Shack VU-210XR that my pair of Zenith DTT-901 tuners are hooked to. Some of my early DTV DX was received on the HD3150. My best log came in November 2006, when I pulled in WJHL Johnson City, TN operating in digital on UHF Channel 58. They're now in digital on VHF Channel 11. This was how their main channel came through.

Digital TV also allows for the capacity to transmit multiple channels on a 600 kHz chunk of spectrum that an analog television signal occupied. The most sub-channels I've seen on one station has been five, for the stations owned and operated by Trinity Broadcasting Network (TBN). Many stations use one channel for a full-time weather channel. On that same night, I pulled in WJHL's weather channel.

One thing that doesn't change, however, is E-layer skip propagation. A handful of digital TV stations in the U.S. operate on VHF Channels 2 through 6. The first E-skip signal that was steady enough to do a video capture of is WRGB Schenectady, NY, which operates in digital on VHF Channel 6. This was pulled in after the completion of the digital transition in 2009.

VHF low-band DTV signals can also be received by tropospheric enhancement. This is from the summer of 2011, pulling in WHBF on VHF Channel 4 from Rock Island, IL. This is the closest VHF-low band digital TV station, at 185 miles.

Many of the VHF digital TV stations operate on Channels 7 to 13. This is my closest VHF High band DTV station, WCIX in Springfield, IL on VHF Channel 13.

My ability to video capture my DX is greatly enhanced with a video card on my computer. In 2004, I bought a Hauppauge Win-TV-Go video card. It's a vital piece of equipment for any DX shack. It does better with digital signals than analog signals. Sometimes, an analog signal can hold long enough to get a video capture. Some countries are still broadcasting in analog, such as Mexico. This one is XHAE on VHF Channel 5 from Saltillo, Coahuila. You can barely read the "Televisa Saltillo" ID in the top left hand corner of the screen. This was received in the summer of 2011.

TV DXing, as far as I've found, hasn't been that much different in the digital age than it was during the analog era. It's just that you need more patience to pull in DX. Give it a try, regardless of whether you have a DTV tuner hooked to an analog TV set, or a new HDTV set. You would need a top-of-the-line antenna to receive DX, though.

No comments:

Post a Comment