Corrections and Updates to USB Tuners and Chip Stories
January 18, 2008
Last week's RF Report was written in the wee hours of the morning after CES ended. After it was published, I found some of the statements made by people I talked to in the booths had been contradicted by press releases.
The Hauppauge HVR-950Q USB ATSC receiver with the ability to receive ClearQAM digital cable as well as over-the-air ATSC broadcasts will use the Auvitek 8522 demodulator and not, as I was told in the Hauppauge booth, the Micronas demodulator.
Unfortunately, I have not found any USB ATSC tuners using the Micronas demodulator.
In the Auvitek suite I saw a Hauppauge HVR-950 demodulator and two Artec demodulators, the T18AR and the T19AR. I was able to obtain a T18AR USB ATSC receiver from PCAlchemy and, based on the drivers, it appears to be using an LG demodulator, not the Auvitek demodulator. At this point, it isn't clear if future T18AR or HVR-950 demodulators will switch to the Auvitek demodulators.
Press releases indicated the new Hauppauge HVR-950Q would use the Xceive 5000 tuner. The Xceive 5000 is a single conversion tuner. According to Xceive, it is the only chip tuner with on-board DSP. The noise figure is quoted at 5 dB and AGC range is 90 dB. I've had good luck with the XC3000 series tuners in some USB ATSC receivers, such as the Pinnacle Ultimate HD stick.
My initial tests in Los Angeles and Miami of the Artec T18AR show it to be a competent receiver, rivaling the HVR-950 in its ability to pull in stations from a short whip antenna. It did as well as the HVR-950 in pulling in the VHF DTV stations in Miami, although at my test site I had line-of-sight (through a wall) to the towers located a few miles away. According to the drivers installed, it appears to be using an LG demodulator and a Microtune MT2131 tuner. I couldn't tell what USB bridge/controller was used. The MT2131 is a double-conversion tuner and did an excellent job of pulling out weaker signals surrounded by much stronger analog and digital adjacent channel signals.
The Artec software generally worked well, including its EPG and closed captioning capability, but I found the way it handles Dolby 5.1 audio resulted in weak dialog on programs from two different network affiliates airing network programming. Using TSReader and the VLC player, the audio was fine.
I'm still hoping to get a tuner with the Auvitek demod, and will report on that in a future column once I've had a chance to test it.