In an analog world, operations on VHF channels (those between 2 and 13) could operate at power levels significantly lower than UHF stations (saving electricity costs), and still cover greater areas. The
All-Channel Receiver Act of 1961 guaranteed that all new TV's must be designed to receive UHF channels, but the major networks were already well established. For digital transmissions VHF channels are very noisy in particular Low-VHF (channels 2-6). It is difficult to receive the signals without the standardized 30' outdoor antenna. Fewer than 40 full power stations in the USA are using Low-VHF channels since the mandatory digital conversion in 2009, and major network affiliates are mostly in large sparsely populated direct marketing areas where outdoor antennas are common. In contrast to the USA, the United Kingdom completely abandoned VHF channels for television when they went all digital.
WPVI-TV had been broadcasting digital signals on channel UHF 64 from 1997-2009, but that channel was recovered by the FCC for resale in March 2008. WPVI-TV was by far the largest urban station to broadcast in the Low-VHF band after the mandatory digital transition in 2009. Next to Philadelphia, the next largest market areas served by a major network affiliate with a Low-VHF channel is Las Vegas, NV served by NBC affiliate
KSNV-DT. WPVI-DT went back to channel 6, where they had been broadcasting analog signals since 1948. The WPVI-TV signal was difficult to receive with an indoor antenna, even within Philadelphia proper.
The FCC granted the station a temporary power increase to 30 kilowatts, following consent given from
WEDY in
New Haven, Connecticut and
WRGB in
Schenectady, New York. Because of potential interference with other stations and with
FM radio, there was doubt as to whether this increase could be granted.
[12] Some viewers did notice an improvement in their signal;
[13] however, WPVI continued to receive complaints regarding the viewability of its digital signal.
[14] The problems have continued to this day.
[15][16] WPVI, along with
Wilmington, Delaware-licensed stations
PBS member station
WHYY-TV (channel 12) and
KJWP (channel 2, a 2013 move-in from
Jackson, Wyoming) are the only Philadelphia area stations whose digital signals operate on the VHF band, as all others physically broadcast on UHF. The FCC advises that a single antenna position will likely not pull both low- and high-band VHF signals (unlike the analog era).
