WHAT WILL THE QUALITY OF OTA HDTV BE IN CITIES WITH LARGE BUILDINGS?

This question was posted by a blogger.com member named Steve in a recent comment; my thanks to him for that great question. This is a big concern for some since city-dwellers live in buildings surrounded by taller buildings that may block the off-air signals.

In areas like these close to the TV broadcast towers, the signals may be strong, but there is also the issue of "multi-path", or, reflected signals that interfere with the line of sight signal and cause "phase variations" in the signal going into the box. Some of the newest DTV tuners, which bloggers and reviewers may mention have a "5th generation or higher" DTV chip set, are supposedly very capable of correcting these multi-path phase variations to allow for a good demodulation of the DTV signal, and a great picture with few breakups (artifacts). However, it also helps to have a directional antenna instead of rabbit-ear or loop antennas that can pick up signals from both directions. Directional antennas focus their reception energy in a single direction, reducing multi-path signals on their way to the DTV tuner, and making its job easier.

Using a directional antenna also allows city dwellers to have options in pointing their antenna. For example, if a resident has a tall building blocking the line-of-sight signal to the point where the received signal (if any) is too weak to result in a picture, the user can simply redirect the antenna and instead pick up a reflected signal. Signals can be reflected off metal structures, like a cell tower, a lamppost, or even a steel-framed building from behind. In these cases, the city dweller may find the antenna needed to be pointed 50, 90, possibly 180 degrees off line of sight to get the best signals and the best DTV picture.

So, if you happen to read this and are having issues getting a DTV picture because a large building is in the way of the direction recommended by www.antennaweb.org or www.tvfool.com, consider a directional indoor antenna (like the Silver Sensor, a TERK with a similar look of the Silver Sensor, or a Winegard SharpShooter), and then try it in different directions, because then the best signal might turn up in the direction you didn't expect.

Of course, if there are few obstructions in the line-of-sight direction, then that is the direction to aim the antenna.

WINEGARD RELEASES VHF HIGH BAND/UHF VERSIONS OF THEIR HD PLATINUM LINE

It took a while, but perhaps they just wanted to get the right design out at the right time. Winegard Company in the Spring of 2008 released five new versions of their HD Platinum series antennas for long range off-air reception, and they are designed to receive channels 7-69. Most markets in the United States after the DTV transition will have their final frequencies in VHF High Band (7-13) and UHF (14-51), and these five antennas will receive these stations from a single direction.

If you are looking to replace your rooftop antenna, then I would simplify the search and focus on the HD7964P model, and then look at it in reference to the TV Fool Web site with its off-air signal predictor tool, which I discussed in an earlier blog. If your DTV channels can be received in a single direction (with a direction range of under 40 degrees) and all the noise figure numbers on the TV Fool predictor results are 5 or greater, then based on the gain numbers claimed for the HD7984 from Winegard, I would expect this antenna to get good reception provided only one DTV tuner is connected to the antenna with RG-6/U cable, with a direct run of 75 feet or less. If there are more tuners to be connected with this antenna and a splitter is used, or more cable is required, then a low-noise preamp may be needed if several of the noise figure results are between 5-15. This recommendation also is for an outside rooftop mount.

If all the predicted noise figures are above 15 for the DTV stations listed, then it may be possible the HD7964P will work in the attic. Based on the dimensions, this design should be easy to fit inside an attic space, allowing over-the-air reception while keeping the antenna hidden from view and not being an eyesore to some.

Winegard rates the HD7964P as a "zone 3" model for suburban locations. If it turns out the TV Fool model has several results at or just below zero, then you will want to consider one of their larger zone 4 models, which are larger antennas but have more gain and more range.