Homebrew antenna for HDTV

Factual Questions
1

I just replaced my vintage CRT TV with an LCD hi-def unit. I was pleasantly surprised to discover that the antenna thingee that I was using (a set of rabbit ears with a small bow-tie UHF unit) is actually giving me more channels with the new TV than I was getting from the old one.

Doing a bit of research, I came across a reference to the Gray-Hoverman Antenna, which this site gives glowing reviews for. Has anyone here had experience with this design, or have any other recommendations for a similar unit?

I live in Toronto, close to Lake Ontario and with an unobstructed line of sight to the CN Tower, which broadcasts a number of TV signals, so even a relatively modest rig should give me good results.

2

Don’t let anyone fool you there is nothing as an HDTV antenna. The TV stations use the same signals only the use them for digital instead of analog.

The key thing to remember is there are three types of TV antenna. One for low VHF (Ch 2-6) one for High VHF (Ch 7-13) and one for UFH (Ch 14-51) (After the switch to digital TV channels 52-69 will be sold off and not used, at least in the USA)

Most TV antennas combine features of the three types, and you need to look at this cause not all channels will broadcast on their digital channels the same as their analog channels.

For instance Channel 7 WKBW broadcasts it’s analog signal on Channel 7, but it’s digital signal on Channel 38. BUT it maps to Channel 7. In other words WKBW’s digital signal sends out information to the TV to make it appear they are still on channel 7 even though they are on channel 38.

If you buy a VHF antenna to try to get WKBW it won’t work well, because the station in on channel 38 not channel 7. So you need to find out what channels the stations in your area are actually broadcasting on. Also remember some stations after analog TV is turned off will return to their frequency for various reasons, as it cost less in power to broadcast on channel 7 then on channel 38. Digital TV doesn’t work well on low VHF (Ch 2-6) so few stations will use those allocations (See: DTV Allocations )

For instance WLS-TV in Chicago broadcasts on channel 7 analog and channel 52 digital. So to get WLS-TV in digital you need a UHF antenna. But after analog shuts off since channel 52 will not be available (remember channels 52-69 will be sold off for other uses, mainly cellphone and Internet wireless), WLS will return to channel 7 for digital. So in this case if you bought a UHF antenna once the transition to digital is over you’d still have to buy an VHF antenna for WLS when it returns to VHF channel 7

So make sure you get the right antenna type and that antenna will work for the stations before and after. You dealers can tell you what type of antenna is best for the stations you need to get

3

I’m assuming, based on what you’ve already said, that your new TV has a digital tuner, or that you’re using a satellite box that has a digital over-the-air (OTA) tuner. Either way, same result: local channels in high-def OTA.

Unfortunately, it appears that Antennaweb is strictly US-only, and I don’t know of a similar tool for Canada. Antennaweb will tell you, based on your address, where your local broadcasting towers are, and also advises you on what type of antenna you need. This helps you point your antenna in the right direction, and helps you pick one of the appropriate size and style. Poke around for something that’ll work for Canada; I just tried one that claimed to have good information, but they didn’t even list all of my local stations, so I don’t think they’re trustworthy.

If you’re pretty darn sure that what you want is coming from the CN tower, and you know the distance from the tower to your house (or at least a good rough approximation), you can pick an antenna based on that information. The Gray-Hoverman antenna you linked to, while it looks like a great antenna, may be too much for your location; if you’re really close to the tower, you may not need something quite so powerful. I suspect, since you’re getting good signal with an old set of rabbit ears, that you could easily get away with something much smaller than a Gray-Hoverman. Additionally, unless you want to become an antenna hobbyist and construct your own antenna, you may be better off just buying something rather than building one from plans.

As a general rule with antennas, higher is better, and outside is best. I can tell you that I put this antenna in my attic less than a year ago, hanging nice and proper on an antenna mast from a rafter, and the results have been most splendid (never less than 90% signal strength). Think about putting something up high, because you’ll almost certainly get better results than something indoors. And you may just want to contact the folks at that Solid Signal site, there’s a link on the left wherein you can tell them your location and requirements, and they’ll email you recommendations about what kind of antenna is appropriate in your circumstances. My antenna was, I think, $27, so it shouldn’t cost an arm and a leg to get great signal.

On preview: the previous poster is correct, anything that calls itself a “High Definition Antenna” is pure marketing. After the switchover, all OTA TV will be UHF, and any antenna that picks up UHF will pick up the digital signals. From there, people just have to decode the signal, and it sounds like you have that part covered.

4

That is incorrect. Many stations will be moving to VHF low-band and high-band channels.

5

I should have been clearer… my new set has both an NTSC and an ATSC tuner built in. I have no interest in getting cable nor satellite, free over the air was good enough for my grandparents, by gum, so it’s good enough for me.

This site suggests that I should be receiving more than I am, although I do get about 70% of the list with the jury-rigged antenna setup that I have (which I built with parts from two older televisions) Some of the stations I get drop in and out, some suffer severe blockyness and freeze-ups at various times. What I’d like is a better rig so that I get more stations, and more consistent reception on the stations I do get now.

As for the actual construction, the plans for the Gray-Hoverman are pretty simple - I can’t imagine that I’d have any trouble putting one together.