DTV Digital TV, HDTV Explained. Written by Drew, January 2008

In Feb 2009, analog TV channels as we have known them for over 60 years, will cease to be transmitted over the air. While this is related to HDTV, the reception of signals at that point will require a digital tuner, (SDTV), not necessarily an HDTV. I recently worked with one of these digital tuners, that was built into a new DVD Recorder, and here is how it works. Over the air TV channels such as Fox 40 tv, and many others, offer sub-channels, (ex 40.1, 40.2, 40.3) etc. Some of this programming is news or weather simulcasts. Some, like on KVIE CH6, are totally separate programs. At this time, all of these can be received. Next year, the analog version, will end. The HDTV sub channel is also broadcast, as one of the subchannels. That channel when viewsed on a normal TV, is not full screen, and appears smaller. The re-use of this bandwidth mainly current UHF channels, is for some public service and also commercial usage. The sought after 700 Mhz area, which is channel 60 and higher has better probogation than others higher frequencies. Coupons for the digital tuner converter boxes, can be found on: DTV 2009

2 coupons worth $40 each are allowed per household. The apps for the coupon program have just begin this month, January 2008. Coupons are supposed to be sent in 2 months. They will expire 90 days from the time they are sent. Conveter boxes will cost approx $60 each, but of course the price may vary, and most likely will drop. Converter boxes will be needed only when receiving tv over the air, with a tv or other tuner that is more than 1 year old and does not have the SDTV digital capability. Satellite and cable subscribers will generally not be affected, but they should check with their signal providers.

HDTV. High definition television simply refers to the resolution of an image. HDTV resolution is either 1920x1080, (1080i and 1080p), or 1280x720 (720p). The second number (1080 or 720) refers to the number of rows of pixels. Theoretically, the more pixels, the clearer the picture. But you won’t notice a difference between 1080 and 720. (Standard televisions SDTV can show 330 rows of pixels. P stands for progressive; i means interlaced. In progressive resolutions, the rows of pixels are refreshed electronically in a series (1,2,3,4, etc.) Interlaced screens skip lines when they refresh (1,3,5,7, etc., then 2,4,6,8, etc.) Some signals are broadcast in 720p, others in 1080i. (There are no 1080p signals, yet.) The type of broadcast is immaterial. Televisions convert signals to the proper resolution.

Televisions are measured diagonally. HDTVs range from about 15 inches to over 100 inches. Additionally, most HDTVs are 16:9s—they measure 16 units (inches, if you like) horizontally to every 9 vertically. Standard TVs are 4:3—4 units horizontally to every 3 vertically. The majority of high-definition broadcasts are 16:9. They are still in the minority; most broadcasts are standard 4:3. You can watch standard broadcasts on 16:9 HDTVs. They will leave bars on the sides. You can zoom the picture to fill the 16:9 opening. That slices off the bottom and top of the picture. Picking the display format (4:3, 16:9, pan&scan) for a given broadcast or DVD is a matter of personal preference, and depends on what is supported by the TV, dvd player the actual content. To pick up high-def stations, it requires an HDTV tuner. Most HDTV sets include tuners. Some, called monitors, do not. A tuner is necessary to receive over-the-air signals. You usually grab them with a roof antenna. If you have cable or satellite, a monitor will suffice. You’ll rent a cable or satellite box with the HD tuner. Sets without HDTV tuners are significantly cheaper.

Types of TV systems. There are four categories: Projection, plasma, LCD and CRT.

Rear Projection. Projection TVs are large and relatively inexpensive. They are also bulkier than plasma and LCD, so you can’t hang them on the wall.
There are several types or rear projection sets

DLP (digital light processing),

LCoS (liquid crystal on silicon),

LCD (liquid crystal display) and

CRT (cathode ray tube). DLP is probably the most common. These sets use mirrors mounted on a chip, along with a light, to create the picture. You may also see a rainbow effect. This is when you see the colors separate on the screen.

LCD LCD sets are rapidly growing in popularity. They’re lighter than plasmas and use less power. Until recently, though, they had a problem with smearing. Motion appeared blurry on the screen. Newer sets don’t have this problem. With an LCD set, look at the response time carefully. This is the time it takes for the pixels to go on and off. I would aim for 8ms (milliseconds) or less. LCDs also have a problem with black levels. If a show is dimly lit, gradations of black can be difficult to see. You can pick up a smaller LCD for well under $1,000. But larger models are more expensive than plasma sets.

Plasma Plasmas have good pictures, although some experts consider LCDs superior. You won’t find plasmas under 37 inches. If you need something smaller, look at LCDs. Plasma displays have a problem with reflections. So they work better in a dark room. Plasmas also have suffered from burn in, historically. A static image displayed too long would become permanently visible on the screen. Newer models are less likely to have this problem.

CRT The fourth type of set is the CRT. These are similar to traditional televisions. They range up to 34 inches. Many consider CRT pictures the best of all. But this technology is dying. The sets are massive. Typically, the tube is about two feet deep on large sets. And the weight can be more than 150 pounds. So, think carefully about where you will put such a set before buying.

Other alternatives. SageTV and the Slingbox are two very different beasts. However, they both allow you to watch your favorite programs from anywhere in the world. SageTV is software that turns your home computer into a DVR. You need a TV feed, so you connect your computer to a cable or antenna. You would also need a TV tuner card in your computer, to handle the signal. You can watch the shows from any computer with PlaceShifter, an additional program. You access your home computer over the Internet to watch the shows. SageTV and PlaceShifter cost about $100, total. In addition, you'll need the TV card.

SageTV also makes The SageTV Media Extender. This piece of hardware bridges the gap between your computer and home theater setup. It will not help you watch your home television from the road. The Slingbox also is hardware. It does not record television shows. Its sole purpose is to allow you to access your television shows. There are a few different models of the Slingbox. Not all connect to your TiVo. You access the Slingbox via the Internet. It uses its own TV tuner or the tuner in your cable or satellite box. You can watch live programming. Or, some models allow you to watch programming you’ve recorded to a DVR.

Neither SageTV nor the Slingbox is better than the other. If you want to use your computer as a DVR, SageTV is an ideal solution. But before you buy SageTV, you might want to give Orb a try. It’s much the same as SageTV. This free program lets you record television on your computer. You can watch live shows from anywhere. Or you can access videos, shows, photos and music through the program. Of course, many people can't conveniently receive a TV feed on their computers. Or maybe you already have a TiVo. In that case, the Slingbox is a better choice. Choosing a Slingbox can be a little confusing. There are three different models. The Slingbox Tuner connects directly to your cable. It has a tuner that can pick up the television stations. The Slingbox AV does not have a tuner. Instead, it connects to your satellite or cable set-top box. And, unlike the Slingbox Tuner, it can control a DVR. Both of these models cost $180.

If you need more options, go for the Slingbox Pro. It has all the features of the other two models. Additionally, it supports high-definition video. You can control up to four sources with the Pro model. It runs $250. Even if you don’t plan to use all the features, this model gives you options you might use in the future. Both the Slingbox and SageTV adjust video quality to compensate for network problems. So the quality of the video may suffer, depending on the speed of your connection. Remember that streaming video is a bandwidth hog. Some Internet service providers penalize subscribers who use excessive amounts of bandwidth.