Will a rabbit-ears-antenna-style TV get clearer reception with an HDTV converter box?

Factual Questions
1

I’ve got an old fashioned analog TV with an old fashioned rabbit-ears-antenna. I live in the heart of NYC and thanks to all the tall buildings I get pretty miserable picture reception – lots of ghosting and blurring. (I tell people that I don’t have a television. I have a radio that glows.)

As we all know, TV stations will cease broadcasting analog signals in February 2009, so I’ve applied for a coupon to buy an HDTV converter box to hook up to my old set and antenna.

That got me wondering, since the new signal will be digital, can I expect my picture reception be sharp and clear?

2

Yes and no. If you get a strong signal, it will be more or less crystal clear. However you simply won’t get weak signals at all - weak analog comes in snowy, weak digital doesn’t come in. Whether you’ll get more or less channels than you currently are I believe depends how close you are to the broadcast sources ( probably pretty close if you’re in the middle of the city ) and the number of obstructions in the way ( possibly a lot in NYC ).

Try plugging your address into this site and see what it says: http://www.antennaweb.org/aw/welcome.aspx

3

Only if you’re lucky.

Digital transmission has the same problem in urban areas that analog transmission has – multipath distortion, secondary signal reception and other problems caused by the signals bouncing off all the tall buildings. If you’re lucky, your DTV converter will lock on the strongest signal and filter everything else out. More likely, you’ll get interference, pixilation, artifacting and signal breakup.

4

I’ve found that a “T” antenna works better than rabbit ears. You can make one or buy one. Look for a FM di-pole antenna at Radio Shack. The linked picture is truncated. They are about 5 feet long at the top and you hang them on the wall next to the TV.

5

You can’t tell till you try.

I live in Chicago 3 miles NW of Sears Tower where the transmitters are. With an analog set and a converter box and a Silver Sensor Antenna I get 3 stations, 2 mostly pixilated. With a digial TV set and my Silver Sensor I get NO stations at all.

With rabbit ears or the silver sensor I get 16 analog stations.

The thing is rabbit ears are only good for VHF channels 2 - 13. Silver Sensor antenna work on channels 14 - 69 (UHF Channels 52 - 69 will be taken from TV and given to cell phones and such)

Digital TV stations map to their old analog numbers. So like in Chicago, WGN-TV is on Channel 19 but it will show up on Channel 9 (it’s analog number). So you need an antenna that gets UHF if you want to get WGN.

On the other hand stations like WLS-TV Channel 7 are on Channel 52 for digital and map to channel 7. So you’d need a UHF antenna to get it. After the converstion Channel 52 will be taken away from TV, so WLS will go BACK to channel 7. So you will need a VHF antenna to get WLS-TV AFTER Feb 17th, but BEFORE Feb 17 you will need a UHF antenna.

You can try

and

http://dtvallocations.com

To see where stations are located after the converstion

6

I live in the suburbs of Houston not a big city, so my situation is not analogous. That said, I get much better reception with my rabbit ears with a digital converter than I did with analog. With analog, for example, NBC is so snowy that it’s virtually unwatchable. With the converter box, it’s crystal clear, as is every other channel I get.

Your mileage may, of course, vary.

7

In NYC, it’s anyone’s guess. You have to try different things in different positions, and maybe something will work. It can vary from room to room, and even between different locations/positions in the same room.

8

The big problem in NYC is multipath. The ability of digital TV tuners to cope with multipath varies widely. In general, the latest tuners do a much better job than earlier tuners. There is still substantial room for improvement and it is an area of active research. I’d give it a try with one of the current convertor boxes, and be prepared to replace it when better convertor boxes become available.

9

Same situation and same results. I was able to pull in everything I got before only it was crystal clear. I played with a lot of combination of rabbit ears, loop, and homemade antennas. I got the best result with a dipole. And for some strange reason I gained signal in one specific room by hooking a loop on the base of the converter where the dipole plugs in. FYI, with the dipole antenna you will need an adapter to plug into the converter.

10

I don’t know what Marxx is talking about. It sounds like we live really close, I’m 3 miles north of the Sears Tower, and there are a lot of high-rises around me (I’m on the 3rd floor of a 6-story) I use this tuner with this antenna, on an HD flat-panel monitor. I get the following stations:

2.1, 5.1, 5.2, 5.3, 7.1, 7.2, 7.3, 9.1, 9.2, 11.1, 11.2, 11.3, 11.4, 20.1, 20.2, 23.1, 26.1, 26.2, 26.3, 26.4, 32.1, 38.1, 38.2, 38.3, 44.1, 50.1, 60.1, 60.2, 66.1

And a couple others that I never watch and am probably forgetting. All stations that broadcast in HD, I get an HD picture. I get many, many more channels than I would have dreamed of with analog. Those stations with “referring” numbers that Marxx was talking about sound like digital cable, not terrestrial signals and station numbers that have been available digitally for the last couple years.

I’ve been using my digital over-the-air receiver since January 2007, BTW, so maybe there have been changes on the analog side that I’m unaware of, but I’m pretty sure that analog channel 7 is the same as digital 7.1

Before I switched to digital, I got 5, 7, 9, 11, 32, 38, 44, 50, and 66. I used to be really frustrated that I couldn’t watch CSI (channel 2, here)

With the digital, there’s still some fiddling. I stretched the antenna all the way across my southern-facing windowsills (8-feet) and still need to turn the fine-tuner a couple stops one way or the other depending on the weather.

11

In most cases, the digital channel number has no relationship to the actual channel used for broadcasting the signal. The box may say “7.1”, but it may actually be broadcast on channel 37.

12

Oh, I think I get it. So it’s not like I could “tune in” the channel that’s actually being broadcast on, because I already am and it just “says” 7.1 on my display? So as long as I’m receiving both UHF and VHF now, I won’t notice any difference when the switch happens.

13

My experience so far has not been good. As mentioned above, poor reception in analog can still be watchable, on digital, poor signal=unwatchable. I’ll be checking into the antenna suggestions mentioned here.

14

The problem with Magiver’s T antenna is that HDTV covers a wide bandwidth, and folded dipoles tend to be narrow bandwidth. I’ve had luck with a sleeve dipole made using some wire, a toilet paper tube, and a coax to twin lead transformer (like on top in the picture here). You could use one of these instead. They’re pretty simple to make.

Cut six 6 inch pieces of wire. Bare one end of two of the pieces and attach them to the transformer. Cut a small hole in the tube, and stick the transformer in the middle, with the two wires sticking out each end. It doesn’t have to be perfect, but you want the wires roughly running down the middle of the tube, one sticking out each end. Trim the ends of those wires so that the total length is 10.5 inches, with the transformer centered. Tape the last four pieces of wire equally spaced around the outside of the tube. Attach to your HDTV tuner using a coax. The two center wires and two of the wires on the outside of the tube are shown in the crappy picture below.

This was designed to work over UHF channels 14 to 59, covering the HDTV channels I can receive now. After the transition, channels above about 55 will be relocated lower. Some will move down into the VHF range (depending on where you live), and this won’t really cover those.

Also, this isn’t very directional, so it might not help much with multipath.



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15

So, how does my TV know what frequency to look for if I try to tune in on digital channel 9.1? Is there a way I have to map this? I just got a new TV to replace my old 12" NTSC set and can’t get any digital channels at all. I thought it was due to distance, but now I’m thinking maybe I left out a step. I’ll be looking through my owner’s manual, but if anyone knows for sure ‘yes, you have to do that’ or ‘no, the TV already knows’, I’d be interested in the answer.

16

Generally, you need to have it scan for channels. If 9.1 is really broadcast on 47, when the TV finds it, the broadcast signal will tell it to map 47 to 9. You may also be able to enter the real channel (47 in the above example) directly, but not the mapped channel (9).

17

Usually, part of the setup is a “Scan for Channels”. The TV or converter box will scan through all of the VHF and UHF channels, looking for ATSC (USA digital TV) signals. Every time it finds an ATSC signal, it stores the actual channel number and the fake channel number in local memory. The fake channel numbers are found in the broadcast signal, and are set by the broadcaster, usually to their old analog channel number. When you enter “7-1” on your remote, it uses this stored information to lookup the actual channel number. As far as I can tell, this whole mickey-mouse scheme was invented to preserve the brand identity of the broadcaster and to avoid confusing users with a new set of channel numbers. There is no technical reason why they couldn’t have continued to use the actual channel numbers.

18

While we’re in here:

Did folks in big cities just have lousy reception in the 1960s and 1970s, before cable TV became widespread?

As a kid in the New Orleans suburbs in the 70s, I remember pre-cable TV looking pretty much OK almost all of the time. Fast forward into the mid-late 90s, when I started living in apartments and such – all rabbit-ears type reception was impossible. Clear pictures were extremely rare without having cable television.

Was something different about the way television was broadcast pre-cable? Something as snowy and crappy as modern-day “apartment” reception would seem to have had a hard time catching on – TV IRL, of course, came on like gangbusters. So people were used to the lousy reception for 30 years, or was something different?

19

I think the tuners in the old days were much better than the ones you get today, since most TVs will be hooked up to cable. I have a 25 year-old balck-and-white portable that picks up many more over-the-air signals than a recently bought Walmart special, whick works fine with cable signals.

20

Thanks, ZenBeam and mks57. I did do the scan when I set the TV up, but it appears I need to do it again with a real antenna (not my old rabbit ears). Now, I just have to decided if the local channels are worth the cost of a real antenna, ha! First, I’ll try a couple of the homemade solutions in this thread this weekend and see if I have any luck.

bordelond: Yes, I had reception that ranged from “can’t get squat” to “crappy” to “hey, that’s not bad”, even when I lived in St. Louis. I’m about 50 miles out of town now, and there’s much more in the “can’t get squat” grouping: can’t get Fox, NBC or CBS at all…other stations are fairly crappy. My sister has satellite TV and when I saw the programming that was available, I figured it wasn’t worth my money. But I’m a wierdo.