Very basic antenna question (don't laugh!)

[Referee]

Do I understand correctly that many vhf digital stations broadcast simultaneously on a companion uhf channel; thereby eliminating the need for anything but a quality uhf (bowtie, etc.) antenna?

[wsteinhauer]

Some stations still use VHF for HD. In Chicago, CBS HD is channel 3, and my UHF antenna can not pick it up. A rabbit ear is required. Check www.antennaweb.org for your location.

[stchman]

Originally Posted by Referee

Do I understand correctly that many vhf digital stations broadcast simultaneously on a companion uhf channel; thereby eliminating the need for anything but a quality uhf (bowtie, etc.) antenna?

I personally hope that there are no VHF HD stations. UHF antennas are much smaller and easier to place.

[Yes616]

Originally Posted by Referee

Do I understand correctly that many vhf digital stations broadcast simultaneously on a companion uhf channel; thereby eliminating the need for anything but a quality uhf (bowtie, etc.) antenna?

I was going to do a joke about a uhf bowtie so I can watch HD dressed up and on the go but nevermind.. lol

I think the question here (and I was wondering as well) is about digital channels and sub-channels. 12.1, 12.2, etc. How does that all work?

I am in the NYC DMA but I am out of range of OTA for UHF especially. OK.. Boonies.. All major NYC channels are doing HD in the UHF range. 2 (CBS) is on 56, etc. It doesn't matter VHF or UHF. My question is this..

Can one tune to 2.1 using a HD VHF OTA tuner and get a HD or digital signal on the SD channel? Or must I go to UHF channel 56? (Using the senerio I say above). And what about sub-channels using a digital tuner? 2.2, 2.3, etc? Wherever they exist OTA.

How does this all work? Can I use a VHF antenna to get channel 2 in HD? Or must I go UHF to channel 56? Can I use a ViP211 to get the digital signal at 2.1 via a VHF antenna? And the others where they may be? Or any HD receiver meaning a set that has a HD receiver built in to the TV itself. Nobody around my neighborhood can get NYC UHF even in SD. 85 miles line of sight with mountains in the way. The VHF SD signal survives the trip OK but I took it down years ago.

This part is confusing and I am sure many of us hope some HD geek comes in to set us all straight. I think I got my question correct in the hopes of proper responses. Of course anyone is welcome to tweak the questions. At the very least, I know what I mean.. lol

[daleb]

Careful, because it is a digital station does not mean HD is always being broadcast. But HD broadcasts are ONLY carried on digital transmissions, and most those digital transmissions are on UHF channels.
The only other way you can receive digital broadcasts not OTA, is if they are carried by Dish.
It does not matter whether you use the Dish tuner or your display tuner to receive the channels in question, the process is the same.

And I think you meant the bowtie antenna is all dressed up with no place to go.

[texasbrit]

First, tuners for digital TV cover both the VHF and UHF bands so that's not an issue.
Second, a digital station has to transmit on a different frequency from the corresponding analog equivalent otherwise they would interfere with each other. So to use your example, channel 2 is an analog channel (VHF) but the station transmits its digital signal on channel 56 which is a UHF channel. In order to keep the "brand" that they have spent money to create, stations can opt to have their digital signal "remapped", essentially given a virtual or fake ID, that makes them look like they are still on the original channel. This remapping information, PSIP, is carried in the digital signal. So the channel 56 signal is relabelled in your OTA receiver box so it looks like 2.1. Digital subchannels like 2.2 are transmitted as part of the signal on channel 56; they take up a part of the bandwidth so the main channel 2.1 has less space for its signal. This is why digital stations with subchannels can often have a degraded HD signal on the main channel.

So to receive 2.1, 2.2 etc you have to have an antenna capable of receiving channel 56 which is in the UHF band. A VHF-only antenna will allow you to receive channel 2 analog but not 2.1 etc. And with most (all?) OTA receivers, to get channel 2 digital you tune to 2.1, 2.2 etc not to the actual channel (in your case channel 56).

To complicate the issue many stations are moving their digital channels when analog goes away in 2009. Some stations are moving back to their analog channel assignment, some are staying on their current digital channel and some are moving to a completely different channel. They will all have to make a decision what they want to call themselves. So to use your channel 2 as an example again. The station did not want to move back to channel 2 for technical reasons (VHF Lo-band channels 2 thru 6 have lots of issues). It could not stay on 52 because channels above 51 will not be used for TV after 2009. So it asked for channel 33 (I believe this is the channel they got but am not sure). One question is - after 2009 will the station now "rebrand" itself to be channel 33? - I assume it will. Then it will appear as 33.1, 33.2 etc on your OTA receiver.

So when you are looking at antennas there are many factors involved. You have to decide if you only want digitals or also analogs (until they go away). And you have to know not only what channel the digital station is ACTUALLY transmitting on (in your example channel 52) but what channel it WILL transmit on after 2009 (in your example channel 33). In some areas, all the digital channels will be UHF so you will only need a UHF antenna. In some areas, they will be a mixture of VHF and UHF, so in those areas you will need an antenna capable of both UHF and VHF reception. And in both cases, if you want analog stations as well, for the next three years, many are on VHF so you need a VHF/UHF antenna.

Does that help??

[Referee]

Yes, I think so. I guess I would need to check with my local vhf stations to see where their digital signals are being transmitted.

Thanks for your help!

[Yes616]

Originally Posted by texasbrit

First, tuners for digital TV cover both the VHF and UHF bands so that's not an issue.
Second, a digital station has to transmit on a different frequency from the corresponding analog equivalent otherwise they would interfere with each other. So to use your example, channel 2 is an analog channel (VHF) but the station transmits its digital signal on channel 56 which is a UHF channel. In order to keep the "brand" that they have spent money to create, stations can opt to have their digital signal "remapped", essentially given a virtual or fake ID, that makes them look like they are still on the original channel. This remapping information, PSIP, is carried in the digital signal. So the channel 56 signal is relabelled in your OTA receiver box so it looks like 2.1. Digital subchannels like 2.2 are transmitted as part of the signal on channel 56; they take up a part of the bandwidth so the main channel 2.1 has less space for its signal. This is why digital stations with subchannels can often have a degraded HD signal on the main channel.

So to receive 2.1, 2.2 etc you have to have an antenna capable of receiving channel 56 which is in the UHF band. A VHF-only antenna will allow you to receive channel 2 analog but not 2.1 etc. And with most (all?) OTA receivers, to get channel 2 digital you tune to 2.1, 2.2 etc not to the actual channel (in your case channel 56).

To complicate the issue many stations are moving their digital channels when analog goes away in 2009. Some stations are moving back to their analog channel assignment, some are staying on their current digital channel and some are moving to a completely different channel. They will all have to make a decision what they want to call themselves. So to use your channel 2 as an example again. The station did not want to move back to channel 2 for technical reasons (VHF Lo-band channels 2 thru 6 have lots of issues). It could not stay on 52 because channels above 51 will not be used for TV after 2009. So it asked for channel 33 (I believe this is the channel they got but am not sure). One question is - after 2009 will the station now "rebrand" itself to be channel 33? - I assume it will. Then it will appear as 33.1, 33.2 etc on your OTA receiver.

So when you are looking at antennas there are many factors involved. You have to decide if you only want digitals or also analogs (until they go away). And you have to know not only what channel the digital station is ACTUALLY transmitting on (in your example channel 52) but what channel it WILL transmit on after 2009 (in your example channel 33). In some areas, all the digital channels will be UHF so you will only need a UHF antenna. In some areas, they will be a mixture of VHF and UHF, so in those areas you will need an antenna capable of both UHF and VHF reception. And in both cases, if you want analog stations as well, for the next three years, many are on VHF so you need a VHF/UHF antenna.

Does that help??

Yep.. That helps. I guess I will wait it out for now before thinking about OTA antennas and see where all the local digital channels actually end up. Thanks.

[texasbrit]

You should find that all your digital channel assignments are complete. Check http://hraunfoss.fcc.gov/edocs_publi...-06-1082A2.pdf