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confused on vhf digital

post #1 of 44
Thread Starter 
i keep reading about some stations having vhf digital signals in the future. how will i be able to view them with my uhf converter box and my digital tuner tv? i thought the boxes were uhf only? if this is true wont i need my old vhf antennas that i threw away instead of the uhf antennas that i bought? somebody needs to enlighten me please.
post #2 of 44
VHF channels 2-13, UHF channels 14-69. What kind of antenna do you have? Broadcasts are still in the same frequency.
post #3 of 44
You'll need an antenna setup that will bring in both VHF and UHF signals. Converter box can handle both. I've got rabbit ears for VHF and double bowtie antenna for UHF combined in a signal joiner. Crossing my fingers the rabbit ears will bring in VHF digital signal when my local station moves back there in February..
post #4 of 44
Thread Starter 
so the converter boxes search for vhf and uhf digital stations? then the old antennas with uhf and vhf elements will be what we need? why are they selling uhf antennas as digital? how do you know if a station the box has tuned is uhf or vhf? so some stations are broadcasting their digital in uhf frequencies now but may be vhf later? i thought the government sold the vhf frequencies and that is what this changeover is all about.
post #5 of 44
Check out tvfool.com to see what is being broadcast in your area.
post #6 of 44
Quote:
Originally Posted by flhusa1 View Post

so the converter boxes search for vhf and uhf digital stations? then the old antennas with uhf and vhf elements will be what we need? why are they selling uhf antennas as digital? how do you know if a station the box has tuned is uhf or vhf? so some stations are broadcasting their digital in uhf frequencies now but may be vhf later? i thought the government sold the vhf frequencies and that is what this changeover is all about.

everything will be the same except you will be recieving a better picture and sound quality. I have found that older rabbit ear antennas with fine tuning help bring in the signal. lower channels (2-13) will be vhf. i dont know exactly know the reason for the changeover, but i know it will help some people who have poor analog reception. the government is selling higher (UHF) digital frequencies for broadcasting but i dont know about vhf.
post #7 of 44
oh and how you can tell is by your channel number if that is what you mean by how to tell if it is VHF or UHF, if its 2-13, its VHF, higher is UHF
post #8 of 44
Thread Starter 
i get digital stations from two totally different locations. i am talking about receiving locations. just to let you know i picked up 2 rca dta800b1 boxes friday night at wally world in the country. i have used the original rca box, the original insignia box, and the newest rca all in the country. my nearest stations are 51 miles away. my newest rca box tuned in 23 channels saturday morning. it appears that when conditions are right the newest rca has the best tuner. the channels that i get consistently which are about 8 in number are showing a slightly higher signal strength than my original rca box.
post #9 of 44
Thread Starter 
ok so if i get lets say channel 6.1,6.2 these are vhf signals. and lets say i get channel 23.1,23.2 these are uhf. ok that clears that up.
post #10 of 44
so the dta800b1 is better? i knew i should have picked one up when i was at walmart...
post #11 of 44
CECB boxes tune channels 2-69. After the transition, nearly all stations will be in the Hi-VHF and UHF ranges. Many stations currently broadcasting analog in the upper VHF range (7-13) have chosen to move their digital broadcast back to hi-VHF once they stop broadcasting analog. Antennaweb.org has a date flag so you can see frequency changes happening later, and tvfool.com shows different graphs for now and later.

I have strong signals; my uhf indoor antenna does a decent job with upper VHF (8+) in analog. I temporarily have a digital channel 4 and I can get that with my uhf antenna, if I aim it carefully. So you may get lucky. Until I lose my low-VHF analog, I am still using rabbit ears or a dipole for the analog stations.

The channel a station calls itself is not necessarily the real frequency it broadcasts on. See antennaweb.org or tvfool.com to know what the real frequency is.
post #12 of 44
Quote:
Originally Posted by flhusa1 View Post

i keep reading about some stations having vhf digital signals in the future. how will i be able to view them with my uhf converter box and my digital tuner tv? i thought the boxes were uhf only? if this is true wont i need my old vhf antennas that i threw away instead of the uhf antennas that i bought? somebody needs to enlighten me please.

VHF channels 2-13 are still used for digital broadcasts. The idea that digital broadcasts are UHF only is just plain wrong.

There are some areas that do not have any VHF digital broadcasts. If you enter your location at http://www.tvfool.com you will find the "real" channels that your local digital stations use. If all the "real" channels now and after 2/17/09 are between 14-69, then you can get by with a UHF only antenna.

All CECBs can tune all broadcast channels ("real" channels 2-69).
post #13 of 44
Thread Starter 
ok i went to tv fool and that is giving me a whole bunch more info than antenna web did. thanks for that and now if i put my rotor up and try different directions i may get even more channels.
post #14 of 44
Quote:
Originally Posted by flhusa1 View Post

so the converter boxes search for vhf and uhf digital stations?

Yes; all converter boxes work with VHF channels 2-13 as well as UHF channels 14-69.

Quote:
Originally Posted by flhusa1 View Post

then the old antennas with uhf and vhf elements will be what we need?

Yes, although you may not need the VHF low band (channels 2-6). Most broadcasters are avoiding these channels for digital broadcasts due to interference problems. So an antenna that receives channels 7 and up will probably suffice.

Quote:
Originally Posted by flhusa1 View Post

why are they selling uhf antennas as digital?

Some are being a bit dishonest. They can get away with it because today, most digital broadcasts are on UHF channels since most VHF channels are already occupied by analog broadcasts. After February 2009, however, this will change and most areas of the country will have several digital broadcasts on VHF channels.

Others may be selling UHF antennas that also receive the higher VHF channels, such as the Channel Master model 4228.

Quote:
Originally Posted by flhusa1 View Post

how do you know if a station the box has tuned is uhf or vhf?

Unfortunately that's not an easy question to answer. Most converter boxes only show the virtual channel, not the real channel. My recommendation would be to go to www.tvfool.com and key in your zip code. They will give you both the virtual and real channels for all the digital stations in your area, both now and post-2009.

Quote:
Originally Posted by flhusa1 View Post

so some stations are broadcasting their digital in uhf frequencies now but may be vhf later?

Yes. In Dallas, for example, analog channels 11 and 52 are currently broadcasting their digital on UHF channels 19 and 51, respectively. After the transition they will be moving to VHF (11 is moving back to 11; 52 is moving to channel 9.)

Quote:
Originally Posted by flhusa1 View Post

i thought the government sold the vhf frequencies and that is what this changeover is all about.

The government did sell several frequencies, but not the VHF ones. They sold UHF channels 52-69.
post #15 of 44
Quote:
Originally Posted by flhusa1 View Post

so the converter boxes search for vhf and uhf digital stations? then the old antennas with uhf and vhf elements will be what we need?

You need more than just rabbit ears.

I recommend buying the Channel Master CM4228 which is small enough it can fit behind your television (on a small stand or pole). I have tested it, and I have received VHF signals as far away as 30 miles. UHF signals can be received upto 40 miles.

You also have the option to do a roof-mount antenna.
post #16 of 44
Quote:
Originally Posted by flhusa1 View Post

why are they selling uhf antennas as digital?

They're selling all antennas as "digital' or "HDTV" antennas, whether they're UHF, VHF, or VHF/UHF combinations. They're not lying, strictly speaking, because those antennas do pick up digital TV signals. They're simply glossing over the fact that they can also pick up analog signals, and most of them are the same antennas that they've been selling all along, even before digital TV started.
post #17 of 44
Quote:
Originally Posted by flhusa1 View Post

ok so if i get lets say channel 6.1,6.2 these are vhf signals. and lets say i get channel 23.1,23.2 these are uhf. ok that clears that up.

No, you have to go by the physical broadcast frequency, not the vanity channel number (which, when possible, matches the station's analog channel number).  You can check a site like tvfool.com or antennaweb.org to find out the true channel number of a station's digital signal.
post #18 of 44
It looks like some stations that are changing from VHF to UHF or vice versa are making an effort to tell their viewers about it, but not all.

For example, WOLO in Columbia SC has analog channel 25 and digital channel 8. Their web site has the following:

Quote:


HOW TO RECEIVE WOLO-DT FREE WIRELESS (OVER THE AIR) DIGITAL TV

* If you have an older analog TV set, you must have a converter box and either an inside VHF/UHF antenna (rabbit ears) or an outside VHF/UHF antenna attached to your TV set. In Feb. 2009 WOLO-DT AND WIS-DT will both be on VHF channels. You will need a VHF/UHF antenna to pick up all Columbia stations over the air.
* When scanning in the local stations remember WOLO-DT is on VHF channel 8.1, 8.2, & 8.3 (real). Channel 25 (virtual) will still show up on your screen, but WOLO-DT is on a VHF channel while other local stations are on the UHF band.

(I like the reference to "wireless digital TV." )

On the other hand, WYFF in Greenville SC has analog channel 4, currently has digital channel 59, and will move to channel 36 in February. I haven't found anything yet in their DTV transition information that says this explicitly. They just have generic information about choosing antennas, with a link to antennaweb.org (which of course shows VHF/UHF status).
post #19 of 44
Though most of the other repliers covered most of the issues, here's my input.

Since this whole transistion started there has been lots of misinformation either by people not reading and repeating wrong info, or by profiteers/scam artists / marketing folks trying to make more money on the confusion around the transition.

1) A lot of people heard about the 'airwaves' auction. For some reason a lot thought that meant they were selling off VHF 2-13 frequencies. When in fact, they're selling UHF channels 52-69.

2) A lot of places in the US have most of their analog stations in the 2-13 range. Existing FCC rules require something like that no two local stations can be contiguous on the dial (to prevent adjacent channel interference). Therefore 12 channels give you, at most, 7 unique channels that can be used in any market, or less if a farther channel might cause interference with locals. Therefore during the transition, even VHF stations were forced to chose a UHF frequency to broadcast their digital signal on. This meant for *many* people, most to all of their digital stations were in the UHF band. However a few markets did get them in the VHF band.

3) UHF requires significantly more power to broadcast (and the higher the frequency, the more the power). Therefore after the transition, some stations will either drop from a higher UHF frequency to a lower one or to a VHF frequency to save power ($$$) and possibly provide a better reception pattern. VHF broadcasts better in some topologies, UHF better in others, each market will decide what's best. It has nothing to do with the digital vs. analog signal. As analog frequencies go off the air, that will reopen slots to broadcast digital from with less power. Also some digital stations were forced into the 52-69 range of UHF that will no longer be available after the transition, and will be required to drop to a lower range as well.

4) Since most stations did use UHF as a carrier for their digital signals during the transition, the marketeers decided to rebrand any antenna capable of receiving UHF as a "HDTV" antenna. Once again,this is confusing terms. HDTV requires digital, but Digital DOES NOT MEAN HDTV. The fact is all of these antennas were the same as the ones sold 5, 10, 20, 40 years ago in many cases. The key thing people don't quite understand --- There is no such thing as a wireless "DIGITAL WAVE". Just like a computer modem over a phone line, the line/wireless itself is still analog. Hardware just modulates a digital signal into an analog sine wave. That's why a 1950 antenna with the same freqency gain specs is as good as a 2008 "HDTV" antenna of the same design. The wave is still analog. It's only how the information is encoded onto it--analog vs. digital that is the difference.

So, take this all together and you'll see why there is confusion, both accidental (assumptions) and purposeful (marketing/scams).

Take a look at AntennaWeb or TVFool. It will show you what frequencies are currently used and what will be used post Feb 2009 in your area. This will let you pick the right antenna. All CECB's receive digital broadcasts on VHF 2-13 and UHF 14-69, though nothing will broadcast above channel 51 in 7 months.
post #20 of 44
I reiterate my advice to buy a CM4228. At the very least. Digital is near-impossible to receive with a set-top antenna unless you live within 15 miles distance of the antennas.
Quote:
Originally Posted by Replay3030Owner View Post

2) A lot of places in the US have most of their analog stations in the 2-13 range. Existing FCC rules require something like that no two local stations can be contiguous on the dial (to prevent adjacent channel interference). Therefore 12 channels give you, at most, 7 unique channels that can be used in any market, or less if a farther channel might cause interference with locals.

That rule no longer applies in today's digital world. DTV channels can be placed side-by-side.

Even now with analog, I have a station on almost every VHF channel.

2 - philadelphia
3 - baltimore
4 - d.c. (sometimes)
5 - d.c. (sometimes)
6 - philadelphia
7 -
8 - lancaster-york
9 -
10 - philadelphia (analog) AND harrisburg (digital)
11 - baltimore
12 - philadelphia
13 - baltimore

I don't understand why the FCC assigned two channels 10s. Harrisburg and Philadelphia are very close together. I guess ATSC and NTSC can sit "on top" of one another with minimal interference?
Quote:


4) Since most stations did use UHF as a carrier for their digital signals during the transition, the marketeers decided to rebrand any antenna capable of receiving UHF as a "HDTV" antenna.

It was one marketer that started the ball rolling, and then the rest followed suit. Put another way:

- Would you want to sell your antenna without the word "digital" attached to it? Nope. Customers might assume your antenna is no good, and you'd lose sales.
post #21 of 44
Question 1: What elements (long or short) on a VHF antenna pick up the low VHF signals and which elements pick up the high VHF signals? (is there a web site that shows this?)

Question 2: Will there be new antenna (for digital signals) that only pick up the high VHF and UHF signals since the low VHF will not be used?
post #22 of 44
Quote:
Originally Posted by pclement View Post

Question 1: What elements (long or short) on a VHF antenna pick up the low VHF signals and which elements pick up the high VHF signals? (is there a web site that shows this?)

Question 2: Will there be new antenna (for digital signals) that only pick up the high VHF and UHF signals since the low VHF will not be used?

1) Long. Lower frequency equates to longer wavelength. The element lengths are usually a given fraction of a wavelength. For log periodic antennas, it isn't a single or pair of elements that receive particular frequencies, the elements work together. But the longest elements are only essential for the lowest frequencies (channels).

2) Yes. Winegard and others have started to market these already.
post #23 of 44
Thanks, CasualOTAer

That means that VHF antenna for television can be slightly smaller once the transition occurs and the lower frequencies are no longer used for television reception.

To rrrrroger: I get Baltimore on channel 2 and Philadelphia on channel 3 (very poor analog reception). I assume that you do as well. I don't get the Philadelphia stations (3, 6, 10 and 12) in digital, but I do get 4,5,7 and 9 from DC.
post #24 of 44
Quote:
Originally Posted by pclement View Post

Question 1: What elements (long or short) on a VHF antenna pick up the low VHF signals and which elements pick up the high VHF signals? (is there a web site that shows this?)

"short" is a relative term. Even the highest VHF channel (13) still uses a ~4 foot antenna. For comparison, UHF uses short, stubby 1/2 foot or 1 foot elements.
Quote:


Question 2: Will there be new antenna (for digital signals) that only pick up the high VHF and UHF signals since the low VHF will not be used?

Hold on a second. Who told you low VHF will not be used? Some cities still have channels 2-6.... example: Philadelphia. You need to check tvfool.com to see if your city will be using VHF-Lo after February 2009.

[edit] [If you live in the Baltimore-D.C. region you will not need a VHF-Lo antenna. Those cities only use channels 7 and up (after Feb 2009).]
post #25 of 44
Some Hi VHF/UHF antennas start at 8. There will be a station on 7 in my area so that wouldn't work for me. As always, read the specs carefully.
post #26 of 44
Quote:
Originally Posted by golinux View Post

Some Hi VHF/UHF antennas start at 8.

That's surprising. Which ones?
post #27 of 44
Thread Starter 
thanks replay for your info. yours and the others let me understand what is going on now and what might happen in the future. with what what you said i might as well keep my setup in the country for now and see what happens after the the cutoff date for analog. i may have to use a different antenna. the stations i get now in the country come and go because of the time of day and other factors like the weather. i wondered why the uhf transmitters of these uhf stations were so much higher than vhf. my metal roof on my house affects my reception. with the antenna higher up i get a weaker signal. when i lower my push up pole the signals get stronger. i think the metal roof is acting as a ground plane. wonder if anybody else has had any experiences with a metal roofed house?
post #28 of 44
In the Chicago area, CBS analog is channel 2, digital currently is real channel 3. Can't get too much lower. Supposed to be real channel 12 after the transition.

ABC analog is channel 7, digital currently is real channel 52. Supposed to be real channel 7 after the transition.

So we will definitely need an antenna that gets VHF reception.
post #29 of 44
Quote:
Originally Posted by rrrrrroger View Post

Hold on a second. Who told you low VHF will not be used? Some cities still have channels 2-6.... example: Philadelphia. You need to check tvfool.com to see if your city will be using VHF-Lo after February 2009.

You are correct, sir. Low VHF will be much less common after the transition, but there will still be a few dozen low VHF stations scattered across the nation. Always check your area to be sure before you choose an antenna.
post #30 of 44
In ZIP 61231, only 4.1 is returning to VHF-LO and is located about 17 miles from the UHF xmitters. Wish us luck.
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