Arresting images

Receiver box seizes HDTV signals

By Brian Dipert, Technical Editor -- EDN, 5/29/2003

Advocates of HDTV have had reason to cheer lately as the prices of HD-ready televisions keep falling and the amount of HD programming keeps rising. Though they get less ink, affordable and dependable tuners play just as important a role in HDTV's overall success. I've recently had the opportunity to extensively field-test one new-generation tuner, Samsung's SIR-T151 ATSC terrestrial receiver set-top box.

First the good news; the SIR-T151's reception characteristics represent a significant enhancement over those of my Princeton Graphics HDT-2000, which is only two years old. The SIR-T151 locks onto signals nearly immediately when you change channels and, unlike the HDT-2000, rarely drops video frames or loses audio-video sync. These improvements occur even though the antenna on the roof of my new home, which I moved into early this year, is only half as high above the ground as the antenna on my previous home.

The robust reception capabilities of the SIR-T151 bode well for HDTV's future fortunes. After all, most folks aren't willing to purchase and put up a roof antenna in order to pick up terrestrial broadcast signals. They'll attempt to make do with a cheaper, simpler in-home antenna; set-top boxes like this one will make that approach a viable option.

I'd argue that price is even more important than reception when it comes to driving HDTV adoption. And the SIR-T151 makes significant strides in this area, too. When Princeton Graphics launched the HDT-2000 at the 2001 Consumer Electronics Show, the press release quoted a suggested retail price of $899. The SIR-T151, in contrast, has an SRP of $499.95. Moreover, as I write this, Amazon.com is listing the box for $310.99 and Epinions.com is reporting prices as low as $265.95 for a refurbished unit.

The SIR-T151 boasts other upsides over the HDT-2000, including the presence of both coaxial and optical digital-audio outputs, a more intuitive and informative graphical user interface, and a universal remote control.

Unlike the HDT-2000, the SIR-T151 does not have six-channel analog outputs, but this omission is, in my opinion, a nonissue. Today's home theater receivers have plenty of digital inputs (which can be either RCA or optical). In my specific case, it's a nonissue because my home-theater receiver's six-channel analog inputs are occupied by my hybrid DVD-Audio/SACD player. Incidentally, Princeton Graphics originally planned to offer a digital audio output as an upgrade option, but this feature has never materialized.

The SIR-T151 isn't perfect, though. Like other DTV receivers I've tested, the device presents users with a confusing conglomeration of old analog and new digital channel numbers (see "Don't forget about the end user," EDN , November 8, 2001). While one receiver might tell me that the digital broadcast I'm watching is channel 35-1 (the ATSC signal for the Sacramento, CA, NBC affiliate, KCRA), another receiver might insist that I'm watching channel 3 (KCRA's NTSC signal). For some stations, the SIR-T151 gives me the digital channel number, for others it gives me the analog channel number. And its behavior is inconsistent with equipment from other manufacturers.

Other observations don't reflect downsides per se, but they do point out the tradeoffs Samsung's engineers made both to achieve a sub-$500 price for the SIR-T151 and to differentiate it from its fuller-featured brethren, the $699 SIR-T160 and the $799 SIR-T165.

The SIR-T151, unlike the SIR-T160, does not include a DirecTV receiver. Although DirectTV employs MPEG-2's audio and video codecs and, as such, uses many of the same silicon resources as those needed for DTV, the incremental hardware and software needed for DirectTV compatibility would likely be cost-prohibitive in this entry-level receiver. Similarly, the cost impact of DVI (digital visual interface) and IEEE 1394 (FireWire) outputs is more easily absorbed by the flagship SIR-T165 than by the more budget-minded SIR-T151.

The SIR-T151 also lacks the ability to receive NTSC signals, a nice feature that my HDT-2000 supports. Samsung reportedly felt that NTSC support would be redundant because many potential customers already own PVRs, VCRs, cable set-top boxes, or other equipment to tune in local broadcast stations. True, perhaps, but for someone like me who doesn't watch enough television to justify a cable or satellite subscription, and who hasn't turned on his VCR in years (thanks to his family's embrace of DVD), the consolidation of multiple features into one box—driven by one remote control and driving one television input—has a certain elegance.

Speaking of television inputs, the biggest problem I have with the SIR-T151 is its lack of RGB output capability, another feature the HDT-2000 offers. This is curious, because the video-processing heart of all three Samsung receivers is an Oak Technology TL851 chip. (This chip has the same technology heritage as the Janus chip that won the EDN Innovation of the Year award in 1999; see "DTV decoder beams HDTV signals," EDN , April 27, 2000.)

The Oak TL851 can output either RGB or component video, so omitting RGB from the SIR-T151 doesn't seem to reflect a cost-saving decision. Perhaps Samsung's intent was to minimize user confusion (and, subsequently, technical support calls). Or perhaps the company wanted to use RGB output as a carrot to lure users who need this feature to the more expensive models.

The two component-video inputs of my Princeton AF3.0HD video monitor are already employed by my Xbox game console and my Sampo DVD player (see "Spring-cleaning: Calibration clarifies the picture," EDN , April 3, 2003). So to incorporate the SIR-T151 into my living-room setup, I'd have three options: Stick a component-video switchbox in front of the television's inputs, transform the component-video outputs of either the Xbox or the DVD player to RGB (by means of a conversion box from a company like Audio Authority or Key Digital Systems), or pony up for a higher-end set-top box from Samsung or some other vendor.