Mat, et al:
I'll throw in 40 years antenna experience, and a year and a half with HDTV installs.
I share your frustration at reception attempts. There are many well intentioned people, that have experience in analog, that will give you wrong advice. Unless you've been in the HDTV trenches, it's a new ball game, new rules. This post will be long, but I want you folks to win at it, so bear with me.
Antennas in the attic rarely work as well as outside, away from roof or chimney, etc. You will almost always have some ghosting, even if you do get a picture. They will work on HDTV, if you're very close, because they eliminate the ghosting problem. Key is, how will you know? If you can get the signal with rabbit ears when you move them around the room, a large UHF antenna in the attic will probably help. But there are lots of caveats: the direction you want to get the signals from are all within a 20 degree or so spread from each other; you can get it away from the wood as much as possible; you use RG6; you don't have to point the antenna at your neighbors three story concrete house and you live in a one story house; you don't have a local UHF analog channel thats really strong; you're not in a gully because UHF is far more lin-of-site than VHF and there's lots more....
But to digress, the best way is to get it up and on the roof. You will, in most cases, pick up 2 to 3 times the signal or more. Roofs don't have a "fixed attenuation", but they generally do, a bunch!
Now the good news. Because most UHF yagi's have a reflector of some type, their front to back ratio, or rejection to a signal from the back side, is quite good. And because this is digital you're going for, it's even less of a problem. Therefore, I have installed many on the side of a house, where it's much less noticeable. You still want to be up as high as possible, gets away from noise sources, and you get the best chance at signal. If the side of house is at right angles, or close, to the towers, and you're not to far away, try this "bedspring", or one that looks like it, a 4221A by Channel Master.
[Link: cmnc.com]If you have to aim it more off-angle, then try something like the Channel Master 4308 or Radio Shack makes a similar one for about $25. The beter way is with the 4248 Channel Master or Radio Shacks big UHF yagi, about $35, and mount it at least 3 ft up and away from roof, or anything else, on a mast. And last, run it through a UHF/VHF splitter, with the VHF side terminated with a 75 ohm resistor, and the UHF side connected to the receiver. This gets rid of any noise or signals outside of the UHF band that the antenna may receive. Mount the splitter close to the set.
One of the major keys to HDTV reception is signal to noise ratio, again a good reason to get it away from your house and attic, where there's lots of EMF, etc, floating around. You are FAR better off to use more antenna and NOT amplify, than vice-versa. This point I've observed many, many times trying to get difficult sites to work. The Terk super-gee-whiz $400 job has been put to shame many times with a Radio Shack special. Its also why I do NOT recommend sharing a downlead with satellite. The DC power they run on is not that clean, and you can pick up odd harmonics that will kill a HDTV signal, even though it will look fine on a meter.
Over the air reception has always been better than cable, when there are no ghosting problems from a difficult location. Cable has to contend with adjacent channel interferance, which the FCC won't allow over the air, and the noise factor of each in-line amplifier before it gets to your house, not to mention a bunch connections and taps. Satellite, and probably cable if they ever do it, uses compression which degrades the signal, so they can get more from the limited bandwidth. Satellite is the only answer for some locations, and it will be a while before local HDTV is going to be beamed down to you, like some areas that now get local analog channels.
Last, if all else fails, try to use the services of someone in your area that has been in the trenches. Try asking the high end retailers who they use, ask for customer references, too. It takes special signal strength meters and a lot of local terrain know-how to make it work in the difficult areas. Beleive me, I have been humbled and surprised many times by what did and didn't work. Your initial efforts could be very inexpensive, and some of the investment could be carried on to a professional install, so if you feel up to it, give it a go. If not, compare the small investment in an installed antenna to the cost of the set and multiply by the number of hours and years you will get pleasure from it all, and if done right, antennas require no maintenance for 15 years or more!
Good luck, and feel free to e-mail me with any questions you may have. My way of saying thanks to all of you, and Mr.Tonks, too, that have helped me with my Pronto questions and more!
Hope this helps. If you have any questions, feel free to send e-mail.
