Samsung SIR-T451 High Definition Terrestrial Tuner
Works well for over the air HD (ATSC)
I bought the tuner at Circuit City to watch the Olympics in high def.  The signal for channel 5 (WMAQ) here was always a little snowy.  Since the tuner has been used, I have to say \\"Wow, great picture!\\" All Chicago stations are crystal clear on my regular TV and when I put the high def on my video projector I get a spectacular 8 foot wide image on the wall of the family room.  I am west of Chicago by 35 miles and have a roof-top antenna (mounted in the attic over the garage) connected to coax routed to this tuner.  Since over the air digital broadcasts use the same frequencies as current TV channels I can use my TV antenna system. Not only am I getting the Chicago stations, but I am even getting Valparaiso, Indiana with good results.  If I got an antenna rotator and put the antenna on the roof I could probably get even more distant stations. <br /> <br />A little background.  The regular TV we have been watching for years is sent in a signal style called NTSC.  The new TV is sent in a style called ATSC.  In the US, the FCC has allocated channels of radio frequencies for TV transmission that we know as channels 2 though 69 on the TV.  Due to advances in computers and in digital signal processing techniques it is possible to send up to 4 regular quality TV programs with ATSC on a channel compared to only 1 regular TV program on NTSC.  Broadcasters have the option of sending 2 high def signals, 1 high def and 2 regular, or 4 regular signals.  They can even send out more if you include some things like weather pictures and other such still or little moving images.  On top of that they can send out data like program content details the tuner can capture and display as text.  When you can tune in ATSC signals you therefore get not just the signals but a whole lot more shows to watch at various levels of quality and a lot of program details.  And it is all FREE to receive!  And it gets better.  For technical reasons, you cannot have two broadcasters transmitting on adjacent channels when using NTSC.  However, it is possible to do that when using ATSC, so more stations will be able to go on the air in the future.  With over 60 channels and 2 to 3 programs per channel we might be able to get 120 to 180 channels in major metropolitan areas over the air.  My, how that might change things. <br /> <br />So, who needs this?  The question arises because more and more TV's already have an ATSC tuner built in.  You could just buy a TV with an ATSC tuner built in. In a year or two (it keeps changing, but now looks like early 2007) all TVs will be required to have an ATSC tuner and there will be no NTSC broadcasts at all.  Well, for me, I wanted to watch the Olympics now and I didn't want to buy a new TV at $1000-2000.  The Samsung can decode an ATSC signal and create an NTSC signal that I can watch on my regular (NTSC) TV.  It also has an antenna out jack, so I can still use my regular TV in the regular way.  I also have an HD video projector, and the tuner output displayed on that is just spectacular.  I have a lot of options on what signal to send where, so I can record to VHS tape and pipe the audio through the stereo, for example. Even with the TV's in the future having a tuner, they are not likely to have a high-def video out jack.  So if you have several displays you want the picture to be on you need a tuner.  In the future I will get a high def TV, but I figure the price will be in the $200 to $1000 range in 2008 compared to the $900 to $6000 range for HD TVs now. <br /> <br />Digital (ATSC) is pretty spectacular.   When you get a picture it is perfect.  When the signal is marginal the picture is still usually perfect, but there are occasional blotchy rectangles that pop up with brief image freezes.  When the signal is really bad you don't get anything, but you wouldn't like an NTSC signal that weak.  The Samsung unit seems to be able to handle the occasional glitches very well, with no problems on the good channels and just occasionalpicture breakup on the station out of Indiana.  <br /> <br />Other reviewers have given good reviews.  My experience agrees with them.  There was one review that commented on poor channel change performance and other issues.  I suspect he needs a better antenna.  With digital there is always some delay during channel changes, which represents the time it takes for the processor to process the digital signal stream, decompress the signal, and create the signal stream to the display. Another issue that was complained about was the inability to go to specific sub-channels directly.  I think that is an incorrect complaint.  Stations can change sub-channel designations on the fly, changing from 2 to 6 signals broadcast from time to time as it suits their needs.  One thing you can do is go directly to the show you want by going to the program guide selecting the show and pressing the enter button.  That gets you there directly with this system.   <br /> <br />There is a nice feature called channel reminder.  You go to one of the program display guides which is an on the screen listing of upcoming programs.  While the guide takes about a minute to load on first use it comes up quickly on subsequent display.  You can select future programs and select a remind feature.  A display pops up 5 minutes before the show and the tuner will automatically change to the channel when the show starts.  <br /> <br />The menu system is intuitive and even fun to use.  You can check signal strength in real time on each channel for aiming the antenna.  There is an antenna out connector so that for analog station tuning you just connect the antenna out to your old standard TV which can then tune in NTSC standard signals.   <br /> <br />My remote is a little slow to respond to button presses.  I suspect it has something on the internal contacts.  It has improved with use.  Aside from that one glitch I am very happy with this unit.  4 out of 5 stars for the remote being a little buggy, and for lack of the HDMI connector option.  Also, the unit requires selection with a back swith for monitor quality.  Should have been menu driven, with option for a pass-through unchanged from the station for those monitors that are able to handle multiformat.  The remote control has sparse controls to control the TV when used as a display device, so you will need the old TV remote by your side.