Digital TV switchover: some basic facts

[Pab Sungenis]

A recent post here had someone asking if rabbit ear antennas would work with a new digital TV. The responses ended up being contradictory with a lot of misinformation on both sides.

As someone with a broadcasting background, and who has been following the digital TV transition over the TEN years it's been in progress (yes, that long), here are some tips to clarify misconceptions of folks here and elsewhere:

Digital TV is already here; it isn't debuting next month.

All of the television stations in the nation are currently transmitting a second, digital signal right now. If you have a new TV with a digital tuner, or a DTV converter box, you can get digital television right now. Follow the instructions, hook up your antenna, and you're ready to go. The sooner you cut the analog cord, the faster you can resolve any difficulties the changeover might conceivably cost you.

There is no such thing as a "digital ready" TV antenna.

ALL TV antennae are digital ready!

Four years ago, I hooked a digital TV receiver (built into a TiVo HD DirecTV receiver) up to the rooftop antenna that had been put onto my home in 1966. I got the full array of Philadelphia digital stations with it. All I needed was an amplifier, which I needed to get any analog signals clearly as well.

There's nothing special about the physical form of digital TV signals, the only difference is the content of them. Think about it as the difference between a dial-up modem and a traditional voice call; both use the telephone lines to carry themselves, and both are just a series of electrical impulses. It's the information that the pulses represent that is different.

General rule of thumb: if your antenna can get a good, relatively clear, signal from analog stations where you are, it will get you a digital signal.

So what the heck is happening on February 17th, anyhow?

It's not a magic date, actually, it's a deadline. It's the day that every TV station in America has to STOP transmitting its analog signal, and be on its final destination TV channel.

To facilitate the transition, the FCC started assigning new channel positions years ago. Every TV station in America got a new frequency they could broadcast their digital signal on. For example, here in Philadelphia, KYW-TV ("Channel 3") was given Channel 26 to broadcast their digital signal, KYW-DT, on. People who are watching KYW-DT actually have their TV tuned to Channel 26, but their TV or converter box is telling them that they are watching "Channel 3.1." The actual channel number is irrelevant, and transparent to the end user.

Making room for duplicates of every TV channel in America was a nightmare. Some of the temporary channels had to operate at low power because they would have interfered with existing stations in other towns. Others had to be opened up in a part of the spectrum (channels 52-69) that are due to be deleted once the transition is complete. After the analog shutoff next month, all of the stations in those higher channel locations will be moving to their new permanent assignments. Most of the lower powered channels will also be moving, and the rest of them increasing power. For example, here in Philadelphia the digital versions of Channel 6 and 12 will be moving to their old analog channels over the coming days, turning off the analog signals a little early to give them time to move.

There is a good way to know what you will be able to get now, and after the switchover, and what type of antenna you will need.

Go to http://www.antennaweb.org and enter your street address. They'll map it and tell you what signals you should be able to receive and what type of antenna would be best to receive them.

[Dangerously Amused]

1. Thanks. This will help a lot of people.

[TexasProgresive]

2. Thanks as well. one other thing

Low power analog channels are not being required to transmit a digital signal so if you wish to receive those and are going to use a converter box you need one that has analog pass through.

[Hokie]

3. Good points but I have to comment on a couple of statements

ALL TV antennae are digital ready!
General rule of thumb: if your antenna can get a good, relatively clear, signal from analog stations where you are, it will get you a digital signal

These are not exactly correct statements. The biggest difference other than digital vs. analog signal type is that all of the new digital channels are on UHF while many of the existing analog channels are on VHF 2 thru 13. While a lot of antennas are good for both VHF and UHF a lot of older antennas are VHF only. The UHF antenna elements are usually the short elements on the front of a combination VHF/UHF antenna. Another big difference is that a marginal digital signal will be unwatchable while a marginal analog signal may have some "snow" but is still watchable for most people. The propogation characteristics for VHF are quite a bit different than UHF. A VHF signal can be received further away for the transmitter than a UHF signal if the antennas have the same gain and the trasnmitted power is the same. I think most of the stations are boosting up ERP (effective radiated power) for their digital channels.

I have been receiving digital over the air HD local channels for about two years and things like multi path propagation that are minor annoyances with analog channels are major problems when you are trying to watch a digital channel and you keep losing lock a few times a minute.

Also, most insects have two antennae while televisions receive on antennas. My antennas professor in college taught us the proper plural on the first day of class.

[pl259]

8. One small bit of technological serendipity is that usually VHF antennas are fairly good

at receiving UHF signals whereas the reverse ain't the case. :-)
(it's even better when the frequencies are very near harmonic) heh heh

[dodger501]

10. You need a special antenna to receive HD signals, though

Our local stations (Mpls.-St. Paul) are transmitting 2,3, 4, sometimes 5 streams on their one channel. So for channel 11, you get 11.1, 11.2, etc.
Usually one is standard, the other HD but often there is alternate programming on the other sub-channels.

[EOTE]

13. Not true.

Once again, any decent UHF/VHF antenna will be able to pick up the HD channels. Before I had cable through HD, I had a really expensive Terk antenna that was supposedly purpose built for HD connected to my (now long gone) tuner box. When I replaced it with my roof mounted antenna (20+ years old), I was able to tune in far more HD channels and they came in more reliably too.

[Statistical]

21. It's like those urban legends that won't die

While your TV displays it as 11.1, 11.2 etc it actually is a single digital channel that contains more than one stream (think of it like a single email with more than one photo).

The actual change (frequency) is not even 11. It is most likely something in the UHF range (channels above 13).
So while your TV shows 11.1 you actually may be tuning (behind the scenes) to UHF channel 37.

Any antenna that has good UHF reception will work with DTV.
If you current antenna has good UHF reception (say channel 27 comes in clear) then it likely will work w/ DTV.

Only things needed are:
1) An antenna w/ good UHF reception

PLUS

2a) A digital converter box & existing analog TV
OR
2b) A TV manufactured after 1996. Even an along tube TV made after 1996 has an ASTC tuner.
OR
2c) An HDTV (all HDTV made after 1995 have ASTC tuner)

[pl259]

28. No, that is absolutely completely wrong. I am watching an HD show right this minute using a 2 foot

piece of hookup wire stuffed into the RF input on my Sanyo hdtv. The Best Buy sales people want you to BELIEVE those stories so you will open up the wallet.

[Hokie]

32. That only works if you are close to the station

When i first got an HD TV I could get 2 stations on a 12" loop of wire hung on the wall. To receive good signals on the rest I put a good UHF antenna in the attic.

[pl259]

34. Yes, well "close" is relative, isn't it? a hundred miles is close compared to the moon.

I merely explained that the other poster was wrong when he claimed it required a "special" antenna...and you have now confirmed my comment! Thanks! :D

[Recursion]

14. My other antenna is a Herzian dipole

[pl259]

29. Fiddlesticks. I have a 40 meter rotary rhombic.

Okay, it isn't easy to rotate...
:evilgrin:

[ReverendDeuce]

4. Great post. Hope people read it...

I've been an enthusiast for about ten years myself. DTV isn't hard to understand and you've made it very clear, so much so that even a novice should understand it.

Remember the 8VSB vs. CFDM battles?

[Lex]

5. Very good info. My complaint is that now that I'm on digital instead of analog

my signal drops A LOT on my channels (I have a converter box and the same rabbit ears). Sure I can get 15 or so digital channels as opposed to 5 that I got on analog, but those 15 drop in and out of a blue screen "NO SIGNAL" constantly, no matter how I turn the antenna this way or that.

[pl259]

6. If you're getting part-time reception, you very well may be able to fix the situation with

an in-line amplifier. They don't cost much at all...under $20. We buy them in bulk from a wholesale supply but I imagine Radio Shack has them.

[Lex]

7. Thanks. I'll check

at Radio Shack for one and see if that helps any.

[Statistical]

24. Most digital channels are low power right now

Durring the transistion (from 2005 till Feb 2009) the broadcast channels need to broadcast BOTH 1) analog channel & 2) digital channel.

Seeing are more people use analog (or did) the analog is genrally the full power, very tall tower, good reception channel.

Lots of the digital channels were hastily put up, sometimes on rented towers, and using low power transmitter.

After Feb 19th there is no need for the analog tower so EVENTUALLY the TV station will move the digital channel to the taller higher power tower.

Reception may improve over time as power & height of digital channels increase


You may also want to increase the height of your antenna is an in line amp does solve the situation. Partial signal may be the result of multipath where you are getting an inconstant "bounced" signal. Putting the antenna higher will allow you to pickup the straight signal.

[Lex]

27. Thanks.

The bounced signal may be right. I'm in a downtown neighborhood with two-story houses, close together.

[Recursion]

35. That's Shannon biting you in the ass

Digital is great, when it's good enough. When it's not good enough, it's absolutely useless.

[RufusTFirefly]

9. Adios, TV!

I rarely watch TV already, maybe two or three times a year at most (Stanley Cup, Oscars, the occasional Congressional testimony). Feb. 17 will simply make official for me what's been unofficial for more than a decade now.

[Lex]

11. Hey, then you can be like this guy:

http://www.theonion.com/content/node/28694

[Touchdown]

16. There's a few DUers who are EXACTLY like the onion guy.

Everytime anything related to television comes up, they have to proudly announce that they do not watch it, and that the rest of us are rubes for doing so. Their condescension gets old real fast.

[Lex]

19. yes, it's pretty funny

isn't it? :)

[RufusTFirefly]

20. Haha. If the topic of the thread weren't TV, that might be true! n/t

[KharmaTrain]

12. This Transition Is Being Butchered

Thank you for your post...

The digital transition began 10 years ago. I've had a digital tuner since 2001 and every over-the-air channel was required to have a DTV signal up and going nearly two years ago. Most have complied.

As you also note, the transition has been a messy one. Many signals are still to be "built-out" or have their power increase for easier reception and others haven't had their final status determined...thus the digital TV out there now won't be what is available in 6 months or a year. I suspect that many powers will be increased. Also broadcasters are talking about widespread use of repeaters and small transmitters to reach areas that area having signal troubles.

The transition has been handled poorly by both the FCC and corporate media. Affordable digital TVs didn't start hitting the market until earlier this year (many still think a digital set costs over $1,000) and the converter boxes are both confusing to operate and have poor signal reception. Worst of all, the people who will be affected are those who are the least technically literate to follow all that's been going on...they have more important things to deal with.

In many ways, I see posts about the transition here as Y2K posts...lots of fears over what in the end will appear to be very little.

[Lex]

18. I hope they do improve digital signal strength. I think it sucks

right now. Setting up the converter box and all that was no problem, even my 12 year old nephew set his up for his mom right out of the box, but the signal strength is crap, imho. They do need repeaters or something.

[loudsue]

15. Ok. Here's a really (really) dumb question:

Is there any productive use of one of those old HUGE satellite dishes that was formerly used to receive tv stations? Are they good for anything? ANYTHING?

[Touchdown]

17. Bird bath for emus, maybe?

:shrug:

[loudsue]

26. Or maybe put a liner in it and use it for a swimming pool?

:rofl: This sucker is HUGE. My MiL died 4 years ago and left her house to my husband. The old satellite dish is out back, and I haven't figured out what to do with it. I was hoping that I could communicate with ET or something....or HAM radio....I dunno.

[Hokie]

33. Not really

Dish Network and Direct TV both use the smaller dishes now customized to hit 2 or 3 satellites. For terrestrial reception an conventional UHF antenna would work better.

[Bill McBlueState]

22. "If you have a new TV with a digital tuner"

How new is new?

In other words, after what date of purchase is a TV almost guaranteed to have a digital tuner? 1990? 2000? 2005? People who aren't sure what kind of tuner their TV has may find this useful.

[Statistical]

25. 2005 to 2007 depending on the size of the TV

The FCC has issued the following mandates for devices entering the US:<1><2><3>
* By July 1, 2005 all televisions with screen sizes over 36" must include a built-in ATSC DTV tuner
* By March 1, 2006 all televisions with screen sizes over 25" must include a built-in ATSC DTV tuner
* By March 1, 2007 all televisions regardless of screen size, and all interface devices which include a tuner (VCR, DVD player/recorder, DVR) must include a built-in ATSC DTV tuner.

Of course manufactures could install an ATSC tuner ealier but these are the last manufacture dates without an ATSC

Also since Jan 1 2006 All TVs without an ATSC tuner (regardless if HDTV or not) must have a warning label advising the consumer that it can NOT receive digital signals.

http://www.twice.com/article/CA6285719.html

As a rule of thumb virtually all HDTV sold since 2005 have had ATSC tuner regardless of size.
Almost all SDTV sold in 2006+ have an ATSC tuner.

[AndyTiedye]

23. There is One DIfference, and It's a Big One. Most Stations Move to UHF. CH 2-6 are Bye-Bye

The actual channel assignment is NOT transparent to the end user.
It affects whether or not we will be able to pick up the station at all.

I get about 8 analog stations now. I get ZERO digital stations. Why?

The analog stations I get are on VHF, most on low VHF (channels 2-6)
which are between 54-88 mhz. UHF stations are barely watchable in
analog here, due to being absorbed by the trees and/or blocked by hills.
These UHF signals are all far too weak for digital, even with a roof
antenna (VHF/UHF) and amplifier.

We are told that the stations will be moving the digital signals onto
their analog frequencies after the changeover, but that is not the
case for channels 2-6. Even stations that have assignments on 7-13
are losing them in some cases: KQED, one of the best of the PBS
stations, is being booted off of channel 9 so the frequency can be
given to KVIE in Sacramento. We won't be able to pick up KVIE on
channel 9, nor can we watch KQED on channel 30, as that signal is
not even detectable here, 25 miles from the station.

It turns out that only 2 Bay Area stations will be on VHF after the
switchover. One already is, and is blocked by a big hill. That is
the one (1) station that Antennaweb says we should be able to pick up.
Not even close.

The local FOX affiliate is being moved from channel 2 to channel 57 :)

A lot of rural people are going to lose ALL TV reception on Feb 17!

[anigbrowl]

30. I predict a flood of Freeper posts on Feb 17 saying obama broke their TV

It's part of the International commie plot to censor everything, dontcha know.

[Hokie]

31. This is the post in this thread that I most agree!

I might add that the problem will be related to the fact that he is Kenyan and not a "natural born citizen".