ABC, FCC Working on DTV Reception Issues
Network, commission addressing low power signals from WLS Chicago, WPVI Philadelphia
By John Eggerton -- Broadcasting & Cable, 6/14/2009 10:17:09 PM
DTV Transition: Continuing Coverage
ABC will be working with the FCC to try and fix the reception problems at WPVI Philadelphia and WLS Chicago, said a spokeswoman for the ABC-owned station group.
Both stations have been experiencing reception problems following the shutoff of analog broadcasts on June 12. WLS was having difficulty reaching high-rise and downtown buildings, while Philadelphia viewers complained they couldn't find WPVI's new digital VHF signal.
"We always believed that we were given an insufficient power allocation, and we will work closely with the FCC to aleviate the situation," said WLS-TV President and General Manager Emily Barr. Julie Hoover, a spokeswoman for the ABC station group, said the situation is the same in Philadelphia.
FCC staffer Bob Radcliff said at a press conference Saturday that the FCC was aware of WLS' difficulties. He did not cite WPVI but said the FCC was doing some field analysis of how VHF stations "are experiencing problems in big cities." He said he has talked with stations and the commission is trying to figure out how to "adjust the technical parameters of these stations to improve their service in the cities."
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In Wyndmoor, PA (19038)
Zero WPVI reception, after the recent launch in June
I did have it before June
Amadeira - 6/27/2009 8:46:36 AM EDT -
There are several potential reasons why reception of WPVI-6 is problematic.
First, make sure your antenna is sufficiently large enough (and resonant) in the low VHF band. I've found at least one installation where reception issues were traced to a UHF-only antenna system.
I'm located about 22 miles from the Roxborough antenna farm, over the side of a slight hill, and can pull in WPVI-DT with no problems using both roof and attic-mounted Channel Master 2016 antennas. I do have Titan 2 dual-band mast-mounted preamps in both locations, used so I can DX from New York City (64 miles over 2 hills) and Scranton - Wilkes-Barre (71 miles over 2 hills).
WPVI was quite strong on my spectrum analyzer on both antennas before raising power.
Second, the proximity of channel 6 to the FM broadcast band is, as other posters identified, going to overload the low-cost DTV converter boxes and some better-built DTV set-tops, not to mention quite a few TVs. By all means, use an FM trap if your antenna has one. If not, an in-line attenuator may help.
Third, the low VHF band is especially prone to interference from impulse noise from motors, compressors, lamp ballasts, etc. These can raise the noise floor high enough to impact the ATSC 15.3 dB minimum carrier-to-noise ratio. Add in multipath and if any portion of the signal waveform drops below 15.3 dB C/N, bye-bye signal.
Only a spectrum analyzer can really diagnose what's going on here. The problem could be one, two, or all three of these factors. But WPVI should have stayed clear of a low band VHF assignment in the first place.
I'm hearing from folks in other TV markets who are having similar problems with low band Vs and impulse noise. One DTV station on channel 5 in West Virginia comes and goes when the retail store below the TV antenna opens up and shuts down for the day.
hdtvpete - 6/22/2009 4:19:47 PM EDT -
can not get wpvi in Folsom Area in Ridley near Ridley High School
David R Lippold - 6/19/2009 9:16:48 PM EDT -
Antennaweb still shows WPVI having a frequencey of 6 for 6.1 and 64 for 6.1. Does anyone know which they are actually broadcasting on. I get
John Liedy - 6/17/2009 1:00:55 PM EDT -
For the Atlanta stations... I still don't see WPXA (ION) and WATC (Independant). WPBA (PBS) seems to have somewhat poor reception. Most of the other stations seem to have very great reception. VHF digital feed: GPB (PBS) and WXIA (NBC)... UHF digital feed: WSB (ABC), WAGA (FOX), WPCH (Independant), WUVG (Univision), WATL (MyTV), WGCL (CBS), WHSG (TBN), and WUPA (CW).
Eric - 6/16/2009 10:13:00 PM EDT
WPVI Gets Power Boost From FCC
06/22/2009FCC Spokesman: VHF Issues Solvable
06/17/2009FCC: DTV Causes No Widespread Disruption
06/13/2009
