Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: HDTV Channel Frequencies  (Read 1125 times)
WA9AFM
Member

Posts: 208




Ignore
« on: January 10, 2006, 08:36:43 AM »

Anyone know the frequencies associated with the new HDTV channels?
Logged
N4LI
Member

Posts: 397




Ignore
« Reply #1 on: January 10, 2006, 10:26:02 AM »

The new digital TV service (“DTV,” it is called.  BTW:  Not all DTV is High-def, or "HDTV," but that’s a discussion for another time) works on current TV broadcast channels.

Most, but not all, current TV stations were given a second TV channel to broadcast in digital on.  These channels are within the current TV broadcast band, mostly in the UHF spectrum.  At a point in the future, now set for February, 2009, all analog channels will go down.  This does not mean that their current DTV channels will remain the same, as the stations can pick between the channels, in many cases.

You will see, though, a change in the TV spectrum after 2009.  All TV will be on channel 51, or below.  These “core” channels are a bit scarce with both analog and digital being on concurrently.  So, your TV stations may be playing musical chairs before all this settles out.

Case in point:  My local Fox affiliate is on VHF channel 13.  Its digital service, which finally reached full-power late last month, is on UHF channel 53.  53 is out of core, and thus, the DTV service may not stay there.  So, when the analogs go off, they will switch their DTV back to channel 13 to remain in “core.”  The FCC will auction off the new spectrum for new services.

I see you are in OKC.  Your DTV stations are on:

KOCO is on channel 7
KTBO is on channel 15
KOKH is on channel 24
KFOR is on channel 27
KETA is on channel 32
KOCB is on channel 33
KWTV is on channel 39
KAUT is on channel 40
KSBI is on channel 51

Now, your channel 50 does not seem to have a second channel.  My records show its DTV on the same channel, implying they will need to switch (what industry insiders call “flash cut”) in the future, unless they find another channel.

But, all this is pretty fluid, and subject to change.
Peter, N4LI
Logged
WILLY
Member

Posts: 286




Ignore
« Reply #2 on: January 11, 2006, 04:10:12 PM »

N4LI:

Am I correct in understanding that whatever antenna one is using now (UHF) will still be fine after all the stations go digital?


In general terms, if one was looking to replace a UHF TV antenna that is falling apart now, what would you recommend?
This is hoping that the antenna will be work right now (channels below 50) and will continue to be useful after everthing goes to digital.


If you care to be more specific, with brand names, etc., please do.  Smiley


Thanks
Logged
N4LI
Member

Posts: 397




Ignore
« Reply #3 on: January 12, 2006, 01:33:52 PM »

Yes, Willy, if a TV antenna works for analog, it theoretically will work for DTV.  But, there are some caveats.

DTV is all or nothing -- suffering from what the TV techies call "cliff effect."  Multipath and signal dropouts can be fatal to decent reception.  So, a better antenna is, well, better.  Look for something with directivity and gain.  Also, since this is UHF for the most part, keep your coax feed short.  Most TV consumer users don't understand the loss of their retail-type coax at these high frequencies.

I can't really suggest a specific antenna.  As with ham radio, there are multiple variables.  But, I can say that several manufacturers have nice lines.  I have owned some Winegard product in the past, and found it pretty good.

I expect to have my first HDTV within the month.  I am looking forward to it.

Peter
Logged
N4LI
Member

Posts: 397




Ignore
« Reply #4 on: January 12, 2006, 08:37:10 PM »

NEØP asks:

"Will these channels work with my existing TV? And will the cable systems pick them up and operate pretty much the same way as they are now? Or will I have to get a new TV?"

The answer is, "it depends."

If you currently subscribe to a cable service, and don't want to shell out any extra money for the time being, you'll be fine for a while.  Even after the analogs go off in 2009, your cable system will simply take the DTV signal of your local and just send it down the cable pipe.  At some point, your system may be all digital, but the cable box will likely translate it into standard NTSC, at least for a while.

Of course, while the picture will look better than the old analog channels due to lack of snow, you won't notice much of a difference.  In fact most cable systems in large cities are receiving the local TV feeds digitally already.

Now, if you're an over-the-air kind of guy, the answer is different.  When the 2009 shutdown comes, you will need some sort of new equipment.  There will be two routes to choose from:

1.  Go buy a new HDTV.  This is an expensive proposition.  But, prices are coming down, and will continue to do so.  HDTV can now be had for well under $1000.  Make sure, though, that your new TV has a tuner in it or you'll need a set-top box (see below).

2.  Buy a set-top box.  There are boxes on the market now that will pick up the DTV signals, and play it on a standard def (NTSC) TV.  They tend to cost around $200, or so.  I bought one on-sale for $90.  They work well, but, again, you are not watching high-def TV, just digital TV.  Still you will notice changes; many TV stations have multiple program streams on their DTV channels -- sometimes as many as 4 pipes on at one time.  When the recent Supreme Court hearings were going on, some stations ran uninterrupted feeds on these secondary channels, which was facinating.  NBC has a full-time weather service many affiliates run.  The selections are potentially endless.

So, there is no needs to panic yet.  Matt Lauer and David Letterman will be available to current TV owners easily for the forseeable future.

Peter
Logged
WILLY
Member

Posts: 286




Ignore
« Reply #5 on: January 13, 2006, 08:58:32 AM »

 by N4LI on January 12, 2006  

"Yes, Willy, if a TV antenna works for analog, it theoretically will work for DTV. But, there are some caveats. "


Thanks.

Thought so.  Makes sense.  Just wanted to be sure and see what other details you may mention.  



"DTV is all or nothing -- suffering from what the TV techies call "cliff effect." Multipath and signal dropouts can be fatal to decent reception. So, a better antenna is, well, better. Look for something with directivity and gain. Also, since this is UHF for the most part, keep your coax feed short. Most TV consumer users don't understand the loss of their retail-type coax at these high frequencies. "

Twin lead instead?   Wouldn't it be lower loss?


"I can't really suggest a specific antenna. As with ham radio, there are multiple variables. But, I can say that several manufacturers have nice lines. I have owned some Winegard product in the past, and found it pretty good.


I expect to have my first HDTV within the month. I am looking forward to it. "
Logged
W6TVK
Member

Posts: 22




Ignore
« Reply #6 on: January 13, 2006, 06:48:52 PM »

Regarding UHF TV antennas for HDTV: I work for a TV/DT station where we use a number of UHF TV antennas for HDTV.

For monitoring our own station and others in our city (Los Angeles) the Radio Shack Yagis with the corner reflector work very well and are inexpensive.
In L.A, DTV stations are presently located between channels 31 and 65.  One antenna covers all those channels easily.  The antennas are available in different lengths for varying amounts of gain.

HDTV is no more difficult to receive than standard NTSC TV on UHF and is probably easier.  Signals are generally strong and ghosting is not a problem.

About the onlysuggestion I can make is to use good quality RG-6 cable and waterproof the connections.
 
Our experience at work has been that an antenna that works OK on standard TV channels works OK on nearby DTV channels.
Logged
K2FIX
Member

Posts: 12




Ignore
« Reply #7 on: January 25, 2006, 06:17:08 PM »

This one's simple for a ham.

How far are your HDTV transmitters ?  Can you hit a repeater from your home which is near one of the HDTV transmitters with moderate or low power ?

You will need a UHF antenna, but that's the extent of it.    I use an antenna one size bigger than needed for my area, as I use it for three sets without a preamp.

Ground everything !  I can work 2m at 100 watts and not cause any issues with my HDTV.

The current Radio Shack Fringe antenna is not very expensive, and has a big UHF section.  If you want smaller, you can go with a UHF only antenna, if you don't need VHF.  In my area, I have gone to the HD feed for all channels except one.

The easiest way to get HDTV is to get it from the air...I've done it this way, and via Cable TV companies, and the best, non compressed picture comes off the air.  The cost of the antenna and coax is amortized VERY quickly compared to the cost of the "Digital Tier".

Once you get used to "normal" colors, not NTSC color, and the clarity of HDTV, it gets real tough to watch "blur-0-vision".

K2FIX
Casey
Logged
AB5RM
Member

Posts: 7




Ignore
« Reply #8 on: January 15, 2008, 11:15:50 AM »

Will Canada and Mexico be making the same transition at the same time? What becomes of the border stations which serve both sides of the line?
Logged
W1PEI
Member

Posts: 6




Ignore
« Reply #9 on: January 25, 2009, 05:27:34 PM »

Canada - August 31, 2011.  Mexico unknown. Should use same converter box as U.S.A.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!