tech spotlight

U Vs. V: In El Paso, It's Up In The Air

KVIA, the News Press & Gazette ABC affiliate in the west Texas town, wants to get to the bottom of the question of which band gives better coverage. It's become an RF test lab after getting the OK from the FCC to to simulcast on its pre-digital-transition UHF ch. 17 at 263 kW and comparing the signal's propagation and reception with that of its current operation on VHF ch. 7 with 32.4 kW.
TVNewsCheck,

KVIA El Paso, Texas, is among the stations whose viewers have experienced serious reception problems since the stations made the switch from a UHF to a VHF digital channel on June 12.

To determine what it should do to restore digital service to where it was before the transition, News Press & Gazette Broadcasting's ABC affiliate is turning DMA 98 into an RF test bed.

Story continues after the ad

Since June 12, KVIA has been broadcasting on VHF ch. 7 with 32.4 kW.

And since receiving a temporary authorization from the FCC last week, the station has been simulcasting on its pre-transition UHF ch. 17 at 263 kW and comparing the two signals' propagation and reception.

KVIA is also looking at the signal of another station in town, Entravision's KINT, which is broadcasting on UHF ch. 25 at 1,000 kW. If KVIA returns to UHF, it too may be able to broadcast at a megawatt.

Kevin Lovell, general manager of KVIA, hopes the side-by-side-by-side testing will give him a better idea of whether his station would be better off returning permanently to ch. 17 or simply increasing the power of ch. 7.

"We have to get a handle on this, but it's clear to me that receiving a digital signal anywhere in the country is a little more problematic than the old analog," he says.

Lovell is not alone in that assessment. Other VHF broadcasters have run to the FCC for help, asking for UHF slots or more VHF power to overcome severe loss of coverage.

According to the latest count, the FCC has granted five other stations temporary permission to simulcast on UHF channels. In all but one case, the stations are on their pre-transition channel.

In addition, the agency has granted six VHF stations power increases and is considering four other such applications.

(The FCC gave the green light to five other stations to increase their VHF power, but all five are still operating at less power than authorized.)

In El Paso, KVIA staff is comparing signals using signal strength measurement as well as with a variety of TV sets and antennas. "It's a little laborious," Lovell says.

At press time today, results of the testing were preliminary and Lovell was not prepared to draw any conclusions. But he points to one "interesting" finding so far.

On paper, the propagation or reach of the VHF signals are greater than that of the UHF signals, he says. "But in the testing in the extremity of the DMA and slightly beyond the DMA, the UHF signals delivered better reception."

But if the testing suggests that moving back to the UHF band is the best solution, he says, KVIA will ask the FCC to make a permanent move back to ch. 17 and use the test results to support its request.

The request, however, would be complicated by the need to coordinate it with Mexican authorities, he says. KVIA sits on the Mexican border.

The alternative is sticking with ch. 7 with a lot more power.

Increasing power would be time consuming and expensive, Lovell says. Among other things, the station would have to buy and install a new mask filter. Its existing one is not rated for higher power levels.

But the expense is a secondary consideration, Lovell says. "The goal is to maximize coverage by whatever means proves best."

Chris Swann, operations manager, said he hopes the testing will answer whether UHF signals penetrate buildings better than VHF.

"There is a theory that it does, that regardless of power, a UHF signal is going to get better reception with a standard set-top antenna than a VHF signal will," he says.

"So it's not as simple as increasing VHF power. We don't want to increase power and find we are still having penetration problems with buildings."

Lovell says the station has received many complaints from viewers by e-mail and phone since June 12, some from within the core coverage area.

"We had some outlying communities that said that they lost us entirely after the transition," he adds.

"It's fascinating," he continues. "I went inside our own building here with a little portable TV and various types of antennas and found differences in receptivity."

Like other stations, KVIA has been advising viewers to rescan their D-to-A converter boxes and to try outdoor antennas or at least better indoor antennas, Lovell says.

"The $64,000 question is: is it their antennas or our signal causing the trouble?"

KVIA's El Paso RF lab may soon have another signal to put under the microscope.

CCA's KTSM, now operating on ch. 9, has asked the FCC for temporary authority to return to its pre-transition home, ch. 16. The agency has yet to act on the request.

Edit Article

Comments (5) -

William Magliocco posted over 3 years ago
A few weeks ago, I picked up a battery operated, portable ATSC receiver. I just returned to my home base of Atlanta after a 10 day trip through the "Great Lakes" region. I make no premise of quantitative analysis with one receiver and its monopole antenna, but I will say my qualitative results were clear-in the Great Lakes region (where power levels are constrained due to the proximity with Canada), VHF ATSC stations were CLEARLY at a disadvantage to their UHF colleagues. I performed simple reception tests in Cleveland, Rochester, Toronto, London Ont., Detroit, Chicago and Manitowoc, Wisconsin. I could not find a single case where I considered the VHF signals to be "easy to receive", and I'm an engineer that maintains ATSC transmitters for a living. The documented reception issues of well known, legacy VHF stations having problems with VHF ATSC assignments were quite obvious. In one extreme case (Rochester, NY), I attempted to receive WHEC-DT (10) and WHAM-DT (13) in Chili, NY. No luck. I had better luck getting WIVB-DT (39) and WGRZ-DT (33) from Buffalo Obviously, certain assumptions made by the FCC were wrong.
William Magliocco posted over 3 years ago
Add Nashville to my list of markets, though it is not in the Great Lakes region.
PhillyPhlash Nickname posted over 3 years ago
We can no longer watch WPVI-TV 6abc (Phila.) in the mornings on our non-cabled bedroom set -- because the picture is degraded when my wife uses her hand-held hair dryer. I wonder how many other "low V" viewers have switched to other stations due to digital interference? The beneficiary in our case is KYW-TV cbs3, which (wisely) refused to broadcast on VHF 3 and stayed on its assigned UHF frequency (which, of course, still shows up as "Channel 3" on the set-top box). Poor Hank down at Channel 6; he should have known this would happen. If he warned his GM and the boss didn't listen, then Disney should take HIM to the woodshed. But maybe this was preordained as a way to reduce viewer confidence in OTA and drive cable subscriptions and all that retrans money? Hank, what's YOUR explanation? I read somewhere that before the transition, you boasted that your V transmitter cost as much to run as a hair dryer; how ironic that the use of a hair dryer is what has driven us to Channel 3 in the A.M.! Why aren't you appealing to the FCC for reassignment to a UHF frequency?
Ed Reid posted over 3 years ago
I think that the man made noise levels that has increase over the years statring with channel 2 and has move up thru the channels were not factor in. As to the question of multipath on VHF vs UHF is still a question is to which provides better results, VHF or UHF. In down town areas where all indoor antenna reception signal is receive by multipath, my thinking is that the higher frequencies are reflected better. The minimun SNR of 15 db to 15.5 db is base upon the receiving equipment, antennas , line, receivers etc. but did not include paramenters for multipath induce noise and man made noise. Some of the noise level are different in different areas of the stations coverage market.
Frogicide Nickname posted over 3 years ago
Above are interesting comments. Although viewers report reception well beyond our NTSC contour on our ch 5 8vsb signal, those reports involve outdoor antenna reception, and though indoor "urban" reception of the low V signal is better than I expected, I did not expect much. Here at the studio the low V signal usually seems surprisingly robust. However, one foggy rainy day, even our 10 element Scala Yagi did not get enough signal to overcome transmission line impulse noise from the nearby high voltage transmission lines. Just to note, NTSC reception had usually been littered with sparklies from the power line, and 8VSB reception almost always is perfect. Still, I am VERY comforted, having the side by side LPTV 8vsb UHF signal.

Classifieds

The Market

Symbol Last Change (%)
Nasdaq 2905.66 +45.98 (+1.61%)
NYSE 8060.43 +115.00 (+1.45%)
S&P 500 1344.90 +19.36 (+1.46%)
Updated 02/04 4:41p ET Quotes delayed at least 20 mins.
Source: Financial Content

Ratings

Overnights, adults 18-49 for February 3, 2012
  • 1.
    3.9/11
  • 2.
    3.5/9
  • 3.
    2.5/7
  • 4.
    1.5/4
  • 5.
    1.5/4
  • 6.
    0.9/2
Source: Nielsen
Reviews
Opinions
Features
  • Robert Lloyd

    Keegan-Michael Key and Jordan Peele, veterans of Fox's sketch comedy MADtv, have a new series of their own, Comedy Central's Key & Peele. It is a genial, at times almost genteel, half-hour in which the pair's obvious niceness shines through even their more pugnacious characters. (Key's version of road rage is to shout, "Selfish!") In a roundabout way, that's the point. The sketches are consistently smart and smartly acted and flow easily from ordinary premises to weird conclusions.

  • Hank Stuever

    Discovery's Bering Sea Gold doesn’t seem at first like it has crossed any new reality TV frontier, relying on elements and structure familiar to the form. Enticingly (to the network), it combines the ocean and the gold and the cold and the reactive testosterone among bad-tempered desperados. To which I am surprised to cry: Eureka, they’ve found it! Bering Sea Gold is a testament to how thoroughly absorbing the genre can still be, when it’s done right.

  • Neil Genzlinger

    All Star Dealers, Discovery Channel's sports-memorabilia addition to the bloated auction/pawnshop/storage locker subgenre of reality television, should have been a winner, with endless stories to draw on and a built-in fan base. But rather than find its own formula, it was content to borrow from existing shows, and it borrowed all the wrong things.

  • Joanne Ostrow

    Kiefer Sutherland displays his softer side in Fox's Touch, a touchy-feely drama merging paranormal, spiritual and sweetly familial elements. shows off his acting chops, long forgotten, in scene after scene. It's heavier lifting than usual for the actor who was often reduced to caricature in 24. Sutherland is all about vulnerability in a show whose goal is nothing short of proving the interconnectedness of human life. We'll see if audiences can tolerate the notion of profound interrelatedness as weekly entertainment.

  • Tim Goodman

    Let's jump right to the most obvious of all sentiments when it comes to HBO's new horse racing/gambling series Luck: Do not bet against David Milch in this one. Like a lot of HBO series, Luck will require patience. It's telling a dense story with nuanced characters and it doesn't feel the need to rush in, like a network series, and hammer home the main themes. But each episode is more enriching, more engrossing than the last and there's Hoffman's superb turn at the forefront, even though his story unfolds with the least rush. Luck is a smart and ambitious series that looks to truly pay off in the home stretch.

  • Mike Hale

    The timing of FX's animated series Unsupervised is unfortunate. A kind of reversed Beavis and Butt-Head — in which the teenage heroes, while losers in just about every way, are also social strivers yearning for suburban domesticity and dispensing Oprah Winfrey-style affirmations — it has the bad luck of coming along three months after the original was revived by MTV. The new show looks awfully pale by comparison.

This advertisement will close automatically in  second(s). You will see this ad no more than once a day. Skip ad