Wednesday, July 8, 2009

A full channel rescan may be unnecessary

I have to agree with almost everything said in ConsumersUnion's pamphlet DTV Made Easy (available at your local public library). The one exception is the advice to rescan for channels every week. If you're getting every channel you expect to get (and want to watch), don't bother doing a full channel rescan. And if you're not getting one or two channels you want to watch and you know they should be there, try a search for additional channels first. Doing a full-channel rescan should be a last resort, because in the process you might lose channels you're already getting, delete your list of favorite channels, and cause yourself other inconveniences. Though I've never heard of a full channel rescan that takes thirty minutes, it's still pretty damn annoying to watch your TV waste time scanning for analog channels and then scan for the digital channels. I wish there was an option to scan only for digital channels. Another possibility is that if your antenna is not correctly positioned, you might lose channels you'd already been watching. The point is that a full channel rescan is not something you want to be doing the minute before your favorite show starts.

In the month after the digital transition, the only channel I was missing here in Detroit was the FOX affiliate Channel 2, WJBK, and I pretty much only watch it on Sundays for "Animation Domination." I had gotten it to come in through a converter box in the living room, but for a month I settled for not being able to watch it in my room. They want me to delete all the channels and do a full rescan? I would try everything else first.

Your digital TV or converter box should have an option to search for additional channels. On my Dynex TV set, it's called an "AddOn Program Search." It doesn't bother scanning through channels that are already scanned in, but it still goes through the analog channels before going to the digital channels.

If that doesn't work, you might want to try dialing the "true" channel number. For technical reasons broadcasters haven't wanted to explain to the general public, most TV stations are not broadcasting their digital content on the same channel they used for their analog content: for example, Channel 14 might be broadcasting at 25-1. But through a little bit of trickery, you can punch in the old channel number you remember so well and your TV will bring up the desired program without burdening you with the information that you're actually tuned to another frequency: so, in the example, you punch in 46 or 46-1 and the TV brings up 25-1 but identifies it as 46-1. (Though to be fair, even in the days of analog, the channel numbers hid more complex information: Channel 14 was actually 470,000,000 to 476,000,000 Hertz, or in some cases, 469,990,000 to 475,990,000 Hertz.)

With some TVs, you might be able to pull in the desired channel by punching in the "true" channel number. How do you find out that number? When Wikipedia is not busy slandering John Seigenthaler, it might actually be able to give you the channel number: in the search box, enter the station's call letters (the four or five letters starting with K or W). The "virtual" number should match the familiar number you already know, while the other number will probably be a bit of a surprise. Channel 7-1 here in Detroit is actually 41-1. The last time I lost Channel 7 on my Dynex TV (doing a full channel rescan, incidentally) I got it back by punching 41-1 on my remote. The screen might be blank except for the text "Channel 41-1" in the corner: this is your chance to move the antenna to try to find the right position. If you're successful, you will see the image and sound come up and the TV will recognize the familiar number, and you can safely forget the "true" number. However, in my case, this doesn't work for Channel 2. Its "true" channel number, for reasons I can't comprehend, is 7-1, the number that wasn't good enough for WXYZ's digital transmission! So dialing 7-1 on my remote control gives me the ABC affiliate, not the FOX affiliate.

Last Sunday I finally gave in and did a full channel rescan in an attempt to get Channel 2 to come in on my Dynex TV. After that, Channel 2 came in clear as a bell. I lost Channel 50 in the process, but I was able to get it back through its "true" number, 14-1.