DTV DXing

[Mr Tubes]

Have any of you tried DXing with Digital TV Tuners? I'm hoping to get a outdoor antenna with a rotor installed this year and try it. I assume anolog is the best for DXing, but soon we won't have a choice! I'm wondering how well it works and if I'll be just wasting my money installing the antenna and rotor since I already have an outdoor antenna in mt attic.

[Steve D.]

Here in he Hollywood Hills I can't pick up any D-tv signals through the converter box. That's ZERO reception with an amplified rabbit ears antenna.
The hills block any signals from Mt. Wilson N.E. of my residence. However, I was able to receive crystal clear KVCR-TV channel 24.1 San Bernardino, Ca. 60 miles dues east. In the warmer summer months I can pickup, very well, VHF OTA analog signals from San Diego. Over 100 miles to the south. It will be interesting to see if D-tv signals make it up here this year. My everyday tv reception is provided by cable.

-Steve D.

[N9ZQA]

DTV DXing is alive and well; just this summer I was able to receive signals from Milwaukee, WI, Grand Rapids, MI, and Bloomington, IL courtesy of some tropospheric events. My antenna setup is nothing to write home about, either - a Silver Sensor pointed out the ground-floor front window of my house.

There are a couple pages devoted to DTV DX work, mostly with tall antennas, preamplifiers, and low-loss coax.

http://www.tvdxexpo.com/dtvhall.html is one of these pages, with screenshots and distance information.

-Jim

[ablethevoice]

I never had much luck TVDXing with our solid state Quasar rig I grew up with, but once in my HS electronics class, we had a late 50s or early 60s vintage RCA tube B&W TV that someone was tinkering around with one afternoon and we suddenly got a fairly solid signal from what turned out to be St. Paul, MN which we were receiving in Albuquerque, NM. That was my only experience with TVDXing. Based on what I've heard and seen so far, I'm not too optimistic that digital DXing will yield much results.

[Robert Grant]

DXing digital TV is harder (or, euphemistically, "more of a challenge") than analog. A digital signal needs to be the strongest signal on the channel (at the antenna input) if one is to have any hope of identifying it. Nearly all DTV transmitters are on channel 7 or above (sporadic-E, the propagation that allows strong reception of stations at distances like, well, from St. Paul or Albuquerque to the Florida Panhandle, is, for all practical purposes, limited to channel 6 and below).
On the other hand, Digital TV is usually identified the instant a station is seen (through the PSIP content), whereas analog stations could only be identified when they presented an ID (the old joke was that the "sporadic" in "sporadic-E" meant it ended one minute before the :00 hour).
There are articles on the internet about digital TV DX.

[ChrisW6ATV]

No digital-TV DX here yet (the S.F. Bay Area is surrounded by hills), but I might install a TV antenna on the top of my 55-foot tower and see what I get. I have a 14/21/28 MHz beam antenna on it now and I did get a pretty good picture on Sacramento channel 3 a while back.

The biggest threat to TV DXing in the future is only indirectly related to the switch to digital TV, since they could have done this at any time already... It is the plan to have (yet more) wireless data services in what they are calling "white space". That "space" is the unused TV channels in any market area. So, instead of picking up TV signals from out of the Bay Area, all the channels could be filled with local junk.

As I noted, they could have approved such a service at any time with or without the switch to digital OTA TV.

[bozey45]

I'll be DXing ANALOG for those LPTV stations that aren't going digital yet and the full powers out of the U.S.; they should skip in like any other station come spring and summer; plus those in Cuba, Mexico and maybe Central America might appear when leat expected. I've gotten Mexico and Cuba and Canada here in Central Fl in the past. As far as DTV DX, I'll give it a try also and see what happens. I have a set with a DTV tuner, plus a converter box (Insignia) thats even better than that set's tuner. Plus a VCR/DVD combo with a digital tuner thats pretty good also; We'll have to see what happens.

[Robert Grant]

Originally Posted by bozey45

I'll be DXing ANALOG for those LPTV stations that aren't going digital yet and the full powers out of the U.S.; they should skip in like any other station come spring and summer; plus those in Cuba, Mexico and maybe Central America might appear when leat expected. I've gotten Mexico and Cuba and Canada here in Central Fl in the past. As far as DTV DX, I'll give it a try also and see what happens. I have a set with a DTV tuner, plus a converter box (Insignia) thats even better than that set's tuner. Plus a VCR/DVD combo with a digital tuner thats pretty good also; We'll have to see what happens.

I don't know if you've had any TV DX experience in the past, but, if you haven't, and you're in Florida, I think you'll be in for a real treat!

Most sporadic-E TV DX reception is along paths of about 1000 miles (E-skip reception of TV stations LESS than 800 miles away is actually relatively rare, even though it is common on the 6 and 10 meters amateur bands). In this "ring" is much of Mexico, Central America, and many Caribbean islands.

Just don't expect to see any E-skip before May, and after August (with exceptions), and remember that E-skip TV is almost always limited to channel 6 and below (higher channels are affected by tropospheric refraction, and you'll get many digitals this way).

[bgadow]

My friend at the TV shop has a pair of NOS antennas which are tuned for only channels 2-6. I wonder if there is any demand for them in the DX community? He special ordered them long ago and the customer never picked them up.

[bozey45]

Yes, i was into TVDX quite extensively in the early 60's when still in high school ('63 grad) and up into the 80's and drifted away because of that thing called a job that seemed to get in the way. somewhere I have a bunch of TV DX QSL cards frm stations all over the U.S. , Mexico and Canada mainly. Also used to get Cuba quite often here on 2-6. Most of the 7-13 stuff was up in the pan handle of Florida and into southern GA and ALA. like Mobile, Montgomery, Albany GA and even B'ham's channel 13. This was with a huge VHF-UHF combo antenna on a rotor that I had. i think I'll even shoot for some within 120 mile LPTV this week when we have several stations going digital on Tuesday as originally planned;our local channel 3 will be killing analog, also channels 16 and 38 and several others; I think most PBS channels are going digital early because of the cost of running both transmitters. There are a number of LPTV stations in central and south FL that should come in when the rest of the stations go DTV IN June; by then the season should be in full swing maybe.

[Robert Grant]

Neither WEDU nor WESH (Channel 2, Daytona Beach) will be returning to their VHF lowband channels for digital, so these channels (the most important for Sporadic-E) will be wide open for exotic DX.

WEDU was the first station I saw by sporadic-E (22 May 1979), and I've seen it literally over a hundred times since. DXers refer to it as an "Es pest".
Though the loss of WEDU here will open the channel for a slim chance of mre distant DX, I'll still miss it. For nearly 30 years, seeing them overtake Cleveland's channel 3 has been a sign that summer is soon to come!

Rob

[bozey45]

Have been able since yesterday to get channel 4 in Miami and channel 4 in jacksonville since WEDU has dumped their analog signal. Yes, I remember during the days before cable tv, WEDU would not even be visible here in this area at all sometimes when conditions were ripe; all you'd see even in Tampa was a mish-mash of lines on the screen and that annoying whistling/buzzing audio for hours on end. The papers here used to have to run articles about that "atmospheric" interference causing loss of reception on channel 3 and they would even run announcements about it; same with the rest of the channels here back then: 8, 10 and 13. There were times they could all be overridden by atmospheric interference and guess thay still can be at least for another 3 months if you;re on antenna. i used to go to my grandparents in Alabama during summer and would even DX there and remember getting WEDU there a number of times. Hope this season is ripe this year, will be the first time for me seriously doing this in a long time.Ha