I sort of miss only having 4 channels.

December 2, 2007 6:18 PM

I recently bought a fancy smanchy Samsung hdtv. However it has a totally different way of describing digital channels than any listing service does. For instance, I look at listings and they what say is channel 709, my tv thinks is channel 9-1. What is going on? Is there some way to get listings and my tv to agree?
posted by aspo to technology (8 comments total)

In my area, channel 709 would be the digital cable HD channel that corresponds to whatever network broadcasts on channel 9. If I use the antenna input on my TV, channel 9.1 would be the over-the-air broadcast of the same network's HD signal.

Does that help?
posted by thinman at 6:53 PM on December 2, 2007

I think I put that badly.

In my area, at least, if Network X broadcasts their non-HD signal over-the-air on channel 9, the HD counterpart for that network will show up on my TV on channel 9.1. Via cable, the same non-HD content arrives on channel 9, and the HD counterpart is sent on channel 709.

It sounds like you are viewing HD content from your antenna (over-the-air), but viewing listings for your area's cable provider.
posted by thinman at 7:03 PM on December 2, 2007

Is this what you're asking about?

Analog 11 in my area is moving to:

Major channel 11 on digital, which is multicast as

11-1 and 11-2 for minor channels 1 and 2

(11-1 is the HD equiv of regular 11, 11-2 does weather 24 hrs)

The physical channel is 35 (that is, the digital broadcast is coming in on UHF channel 35.

The only thing the major channel number does is let the tv station keep calling themselves "Channel 11", so they don't have to change their logo, business cards, etc.

So, when I flip through over-the-air channels on my TV (also a Samsung!), I get analog 11, digital 11-1, and digital 11-2. Analog 11 is the one that will go away in 2009.

And to make it slightly more confusing, in my area Digital 11-1 is now channel 432 on cable, and Digital 11-2 is now channel 216 on cable. For now Analog 11 is still cable 11 here.
posted by gimonca at 7:12 PM on December 2, 2007

(Some of the links/anchors in the link above are goofy--try clicking on FAQ #9 for more info.)
posted by gimonca at 7:20 PM on December 2, 2007

My TV does this too. Unfortunately I can't help with the problem, since we got TIVO shortly after getting the new TV.
posted by demiurge at 7:21 PM on December 2, 2007

If you are viewing TV via cable, with NO antenna, then I can explain but it's pretty complicated.

Again, this assumes that you have cable.

Cable channel numbers, as seen on your set top box and in your program guide, are VIRTUAL numbers. In the old days of 2-digit channels, the channel you were viewing actually corresponded to an "RF channel" on the cable. When you went to channel 65, your TV or set top box (STB) was literally tuning a radio in the box to radio frequency (RF) channel number 65, and taking the one service there and displaying it.

But with the advent of digital cable, and hundreds of channels (3 digits!), that all went out the window. Now the cable company could stuff a dozen or more services ("services" is the better term to use in this case) into one RF channel. They basically pile up in that channel, and then your set top box and new digital TV has the smarts to pull them apart.

Well, the virtual numbering plan in the cable system is proprietary, and requires the STB to decode. So in your example, they have one or more services at RF channel 9, but it's actually virtual service number 709. But your TV doesn't know about the virtual service numbers, it just knows that it found it at RF channel 9. So it gives it the number "9-1", and if it finds any others piled up there at RF channel 9, it'll call those 9-2, 9-3, etc.

Obviously this is a big PITA, but you'll probably figure it out after a while. You'll just have a cheat sheet that says "709 is actually 9-1" and so forth.

By the way, those are FREE HD channels your TV is picking up. YOU DO NOT NEED TO PAY EXTRA FOR HD SERVICE FROM YOUR CABLE COMPANY. All of the *broadcast* networks must be carried for free on your cable (I'm simplifying, it's more complicated than that). But if you want a cable-only HD channel (say, Discovery HD) then you will indeed need your set top box for that. Well, you should ... maybe you'll get lucky and find that your TV can directly pull that in too.

Man, I must really be avoiding some task to have typed all that ...
posted by intermod at 8:48 PM on December 2, 2007 [1 favorite]

Your profile implies that you're in the Bay area. You will find an obscene amount of information about HD on Comcast here:

http://www.avsforum.com/avs-vb/showthread.php?t=793017

A lot of it may be over your head. Further, I'd caution you to not sucked in over there. There's a lot of guys with too much time on their hands hanging out at AVSforums ...

Welcome to the wild world of digital TV. It's going to be pretty confusing for a couple more years, and then will start to calm down in 2009 once the analogs are shut down and the digital repack happens.
posted by intermod at 8:56 PM on December 2, 2007

Aspo didn't give enuf info (cable or over-air? if cable, was it basic cheapo service?). But yes, intermod is right.

Your Samsung probably has a QAM tuner built in. THe TV makers do not discuss it and do not print anything in instruction manuals or spec sheet. It's really true... the cable companies must relay to users with QAM tuners all digital (including HD) transmissions that are unencrypted. But many companies (like the hideous Comcast) shift the line-up constantly, so that we QAM-sters have to rescan to find the new arrangement. Here in Seattle area, I get about 9 or 10 free HD channels (some broadcast HD only occasionally, some most of time, esp. evenings). It's a BLAST!! I pay only for basic cable, that is 14 bux a month. WIth QAM one cannot get fancy unencrypted HD transmissions (HBO, movie channels, etc).

Try sticking with the AVSForum website. It's difficult but you'll find a chat concerning your specific locality. Someone there (those brainiacs and profesh techies) will probably have typed up a list of the digital and HD stations that you can get unencrypted with your QAM tuner. If you don't find a smarty-pants, you should spend about 2 days with your remote, and just go panning around the hundreds of stations. You'll have to enter "98-1, 98-2, 98-3, etc etc, 112-1, 112-2... " I mean that's just a sample to show you the "algorithm". It's hundreds. Basically, if it's like here in my area, all the action starts in the 70s and runs to the 117s or so. But my Comcast lately has arranged the HD signals in particular very neatly, making them "-1s" after the low number that the so-called station is known for. E.g., my ABC HiDef is 4-1, my PBS is 9-5 (PBS here has 4 or 5 services), my FOX is 13-1, etc.
Have fun.
posted by yazi at 10:40 PM on December 2, 2007 [1 favorite]