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.
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.
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.