2 Comments

1. Donald Chepurna

   Posted May 16, 2013 at 4:34 PM

   I have just a basic question about television signals- do the digital channel numbers correspond in frequency to the older analog channels? Do digital signals have the same 6mhz bandwidth of the analogs? Judging by the antennas I have seen for recievers I would guess that most if not all broadcast television now operates in the UHF spectrum

2. RussB

   Posted May 17, 2013 at 5:47 AM

   Well there are two channel numbers in use today in television, the RF or actual channel and the virtual channel, the one presented to the public. The station KTVU was on channel 2 for analog broadcasts but broadcasts on channel 44 for digital. Since broadcasters had spent lots of money over the years promoting their analog channel they did not want to loose on that investment, so the virtual channel was born. All DTV tuners look at the PSIP information sent out by every station, that tells them the virtual channel for that station, and they remember the virtual channel number for all the stations it knows so when you punch in channel 2 the DVT tuner will actually tune to RF channel 44 and receive the broadcast from KTVU.

   And yes, every DTV channel in the United States is 6 MHz wide, just like the analog channels were.

   And again yes, most but not all television stations are in the UHF band now, the lower VHF channels don’t work well in digital, but everything from 7 up works pretty well. Here in the San Francisco Bay Area we have two VHF channels, 7 for ABC and 12 for NBC. Much lower power is required for VHF.