The optimism is warranted sometimes. I was out last night and had my laptop with me, so just for grins, I hooked up the DTV stick with a small whip antenna to see what was coming in. I was in Mesa AZ and was pulling in UHF DTV stations from Tucson, about 100 miles away - KVOA, KUAT, KMSB and KTTU. All are situated about 7500' above Mesa's elevation, but none operate at full UHF power because of their elevation above Tucson. (KUAT @ 667 kW, KTTU and KMSB @ 480 kW, KVOA @ 405 kW, vs. max 1000 kW for UHF.) Tampa and Ft. Myers stations all sit at about 1450 - 1500' above avg terrain.
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Any areas of the US that will LOSE OTA reception as a result of DTV?
- Thread starter Tim from Springfield IL
- Start date
I'm in the western Antelope Valley closer to Gorman, the area is about to have a new city built, yet will have zero over the air DTV and the nearest cable tv drop is 20 miles away. Bakersfield and many Fresno analog cover the area well, but all the DTV's have a deep null to the south, KERO 23 DTV is Ch 10 with 4KW; with zero signal here.
Ridgecrest already has DTV with translators for NBC and KTLA with KABC and KTTV to be flash cut when the budget permits.
Steve
www.xrqk.com
If it hasn't already been mentioned, add Olean/Allegany/St. Bonaventure, NY to the list. Roof antennas in the area are able to pick up WGRZ-TV and WIVB (NBC and CBS from Buffalo) currently, but none of the Buffalo digital signals will be receivable in that area.
pabsungenis said:
The signals for WGRZ, WIVB and WKBW are all supposed to reach Olean, and in the case of WIVB and WKBW, well beyond. Also, Jamestown station WNYB's post-transition signal is supposed to reach Olean. Of course, theory and practice don't always match, and the terrain around Olean might pose a problem. What will be interesting to see is how reception is in the city vs. on the hilltops. Also, people in Olean will now need to use a UHF antenna, because even though the major network stations will still ID as 2.x, 4.x and 7.x, they will actually be on channels 33, 39 and 38, respectively. The 3 Buffalo stations are all operating their final post-transition facilities already.
dhett said:
Good point. UHF came late to the Buffalo market (despite NBC's attempt with WBUF-TV) and most antennae down on the tier are VHF only, or at least VHF oriented.
w9wi said:
It's been years since I've been to Olean, but IIRC, the ridge was to the NW, right in the line of the Buffalo signals. I'll be in WNY next weekend and would love to get down to Olean to check it out, but it's probably not going to happen. Still, you would think that if they're getting analog signals, they should still get the digitals.
I mentioned this in another thread, but Nogales, Arizona, will probably lose OTA reception of American television. The only stations available there are five Mexican stations (Televisa 2, 5 and 9, and Azteca 7 and 13), plus KMSB 11 from Tucson, broadcasting from the Santa Rita mountains. KMSB moved its digital signal to the antenna farm in the Catalina mountains, north of Tucson, so it no longer serves Nogales, which was its city of license before 1991.
No LPTV stations serve Nogales. KPCE-LP, licensed to Green Valley, was the closest, also in the Santa Rita mountains, but they just moved their signal to the Tucson mountains west of downtown Tucson, and changed their city of license to Tucson.
No LPTV stations serve Nogales. KPCE-LP, licensed to Green Valley, was the closest, also in the Santa Rita mountains, but they just moved their signal to the Tucson mountains west of downtown Tucson, and changed their city of license to Tucson.
Tim from Springfield said:
Yes.
Grand Marais, MN is currently served by translators of Duluth market stations. These translators will shut off at the time of the DTV transition (not by law, but according to the plan of the stations). Grand Marais is about 105 miles from the Duluth DTV transmitters, so there's very little chance anybody will see them without their own 200 or 300' antenna tower. There's also WBKP in Calumet, MI, which comes in over the lake on channel 5, but I have doubts as to whether their VHF DTV station on channel 11 will make the 140-mile path (their antenna is located a distance from the analog's antenna).
I'll throw another problem out there: predicted coverage maps are not all that accurate - and it's particularly true for DTV stations.
I suspect that many stations and the FCC think these signals will cover areas that in reality will get nothing. The solution for this will ultimately be for stations and the FCC to do some tinkering with transmitter strength and antenna height.
What I'd love to know is what people living in Hillsboro, Texas see when they fire up a DTV receiver and tune to channel 9.
It's the frequency for both WFAA in Dallas and KCEN in the Waco-Temple-Killeen market. Hillsboro is about half way between the two. The predicted coverage almost overlaps. Either there's a gap there where neither station can be received or there's an area where both can, depending on which way you have your antenna pointed. I would think that such an overlap would play hell with someone using rabbit ears oriented North/South.
I suspect that many stations and the FCC think these signals will cover areas that in reality will get nothing. The solution for this will ultimately be for stations and the FCC to do some tinkering with transmitter strength and antenna height.
What I'd love to know is what people living in Hillsboro, Texas see when they fire up a DTV receiver and tune to channel 9.
It's the frequency for both WFAA in Dallas and KCEN in the Waco-Temple-Killeen market. Hillsboro is about half way between the two. The predicted coverage almost overlaps. Either there's a gap there where neither station can be received or there's an area where both can, depending on which way you have your antenna pointed. I would think that such an overlap would play hell with someone using rabbit ears oriented North/South.
Those maps look real optimistic. Are they realistic? For one thing they are usually very circular, which is strange, considering that DTV is a completely "hit or miss" proposition. And that many people well within the primary cone have had major reception issues.
Maybe done by the same engineering firm that gave us the Yugo?
Maybe done by the same engineering firm that gave us the Yugo?
The FCC's coverage contour is an indication of how, with a roof antenna placed 30 feet above ground, the station would have a certain amount of energy in it. This map is used to show which area is "protected" coverage, such that a station could be a repeater within the circle or something.
It's a pretty inaccurate map. I receive 6 UHF digitals all the time, I'm only within the coverage contour of two of those, then there are two more UHF digitals for which I am within the coverage contour and don't usually receive.
I'm not quite sure why the FCC still uses those maps, but they do.
- Trip
It's a pretty inaccurate map. I receive 6 UHF digitals all the time, I'm only within the coverage contour of two of those, then there are two more UHF digitals for which I am within the coverage contour and don't usually receive.
I'm not quite sure why the FCC still uses those maps, but they do.
- Trip
tripinva said:
And really, they don't for DTV. See http://www.fcc.gov/mb/audio/bickel/curves.html.
I would imagine they still use them for analog services because for years, that's all they had.
And really, for the specific regulatory reason you cite (for determining whether a station-owned translator should be allowed) it makes more sense than using more accurate methods. Admittedly that's a pretty narrow application, and for the purpose of determining whether DTV service is provided the newer, more accurate methods are certainly a good idea.
To address others' posts...
The maps are designed to show the area within which a station delivers a particular signal strength at a particular proportion of locations for a particular fraction of the time. (F(50,10) = 70dBu: the station delivers at least 70dBu of signal to half of locations 10% of the time) Of course there are other reasons (interference from other stations) that a station may not provide useful service even if it does provide a strong enough signal.
At the time the analog regulations were created, it was simply not possible to take terrain into account when plotting these maps. It would have taken forever to calculate each Longley-Rice square with a slide-rule, and probably into the early-mid 80s computers wouldn't have been much better.
Regarding WFAA/KCEN, do note that WFAA is returning to DTV channel 8 after Transition - so this problem will go away. It was a pretty big challenge getting everyone a second channel while still trying to avoid assigning channels 52-69 (especially 60-69) - AND leaving analog on the air until 2009. Some interim assignments are pretty bad. I think we'll find the permanent situation, once the analogs are gone, a lot better.
w9wi said:
And KFWD-DT will be moving to WFAA's abandoned channel 9. So the problem will still be there, though the KFWD signal will be directional where the WFAA digital signal is omnidirectional, which will make it somewhat better.
As I recall, WFAA was granted channel 9 by the FCC, while KCEN had their digital reassigned from channel 50 to channel 9. This allowed KBTX-DT in Bryan to be reassigned from channel 59 to 50.
I agree with you, there are some really really bad assignments out there even post-transition. I think 29 in Philadelphia is a bad one, as is 33 in New York. 42 in Annapolis and 41 in Baltimore. 18 in Los Angeles and San Diego. All could have been worked around easily I think. There are many more than that, just that I have specific plans that would resolve those. (Move WUVP to 33, WCBS to 23, WFTY to 34; move WMPT to 43; move KUSI to 25)
- Trip
tripinva said:
Trip,
You can also add this to the "bad assignments" category: 19 in both Chicago (WGN-DT) and Peoria (WHOI-DT). Both signals will be battling it out somewhere in LaSalle County (in Chicago DMA, but much of the rural areas around the Tonica/Lostant/Rutland/Dana areas who rely on OTA probably can only get the Peoria stations--thus LaSalle County could have even been a case for a split DMA county) and in Livingston County (around Pontiac/Odell areas--Livingston is in the Peoria market, but was formerly part of the Chicago DMA and still may have households relying solely on Chicago stations, particularly around the Dwight area).
Tim from Springfield said:
I'm aware of that one and it's just stupid in my opinion. Why did WHOI choose to return to channel 19? They should have just stayed put on 40 and been done with it. Would have made everyone's lives easier.
Really, I think WGN-DT might end up moving. They have stations on all sides (WHOI, WMTV, WXMI) and it's just turning into a mess. I don't know where they'd be moving TO, but I think they might look into it at some point.
- Trip
tripinva said:
Considering that the roof of the average 2-story home is at just about 30' from the ground at its peak, that's not unrealistic.
The maps are an approximation and do not take terrain into account. When broadcasters look to site a transmitter in an area that would be shown to cause interference to a co-channel or taboo-channel signal, they usually use another measurement (Longley-Rice) which does include the effect of terrain and provides a much more accurate picture. I use the FCC coverage maps because they're the best information I have, and I've found them to be pretty reliable - even conservative in some cases. In places like Florida, there isn't much terrain to take into account; the highest point in the state is only about 345' above sea level, and that's on the Alabama border in the panhandle, so I'd put greater trust in the maps in a place like that than, say, in the Blue Ridge Mountains, or any other mountainous area.
Still, sometimes there are dead areas. I'm barely 5 miles east of the antenna farm in Phoenix and have a clear line of sight with no trees, buildings, or other objects to cause interference. In spite of that, I usually cannot receive KFPH-CA at my house, yet when I go 25 miles north of the mountain, there it is, clear as a bell. My house definitely within the coverage area, but I'm not covered. But that's not a function of the signal not being strong enough; it's some other interference. I could even be (*gasp*) a transmission at variance with its stated parameters, although less likely here than in a rural area.
I'm not an engineer, so if any could answer this, I'd appreciate it: in the case of a side-mounted antenna, could there potentially be interference from the tower itself for those located opposite the side on which the antenna is mounted?
Perhaps the FCC needs a disclaimer, saying "Your mileage may vary"?
I'm not an engineer either, though I'm one year into studying to be one. =)
Definitely, the tower can cause interference to the signal in a side-mount situation. The most famous of these is WECT-DT in Wilmington (just because of the early transition date). Raycom didn't want to "waste" energy by putting the antenna facing toward Wilmington itself (and thus beaming a bunch of signal over the ocean), and so they put the antenna on the west side of the tower instead. Now, WECT-DT is the least reliable signal in Wilmington. I can vouch for this personally, as last time I was in Topsail, I couldn't kill WUNJ-DT (same tower) but WECT-DT was incredibly finicky and wouldn't stay locked for any period unless the antenna was placed just right.
I can also vouch for the inaccuracies of the maps (speaking of the Blue Ridge mountains). The Roanoke TV stations carry all the way out to the eastern edge of the DMA. I've done signal testing just outside of Keysville--93 miles from Poor Mountain--and received 7, 10, and 27 digitally (plus 13 from Lynchburg) with an indoor antenna and an amp. (Got just 10 and 13 digitally without the amp) But if you believe the coverage maps, the signal drops off after about 70 miles, in the Brookneal area.
- Trip
Definitely, the tower can cause interference to the signal in a side-mount situation. The most famous of these is WECT-DT in Wilmington (just because of the early transition date). Raycom didn't want to "waste" energy by putting the antenna facing toward Wilmington itself (and thus beaming a bunch of signal over the ocean), and so they put the antenna on the west side of the tower instead. Now, WECT-DT is the least reliable signal in Wilmington. I can vouch for this personally, as last time I was in Topsail, I couldn't kill WUNJ-DT (same tower) but WECT-DT was incredibly finicky and wouldn't stay locked for any period unless the antenna was placed just right.
I can also vouch for the inaccuracies of the maps (speaking of the Blue Ridge mountains). The Roanoke TV stations carry all the way out to the eastern edge of the DMA. I've done signal testing just outside of Keysville--93 miles from Poor Mountain--and received 7, 10, and 27 digitally (plus 13 from Lynchburg) with an indoor antenna and an amp. (Got just 10 and 13 digitally without the amp) But if you believe the coverage maps, the signal drops off after about 70 miles, in the Brookneal area.
- Trip
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