Some advice from Ing. Jan Pazral,
Chief Engineer,
WXXI Public Broadcasting Council



With the deadline for the analog TV shut-off quickly approaching, more and more viewers are acquiring the DTV converter boxes. Subsequently, the WXXI engineering dept. is getting increasing number of phone calls from viewers asking for help with the over-the-air DTV reception.

Please read this article before you call WXXI, as you may find answers to your questions here.

In order to adapt a legacy analog TV set for the new digital reception, two items are needed: A DTV converter box and an antenna. No converter box will work without an appropriate antenna suitable for the DTV reception.

Unfortunately, the old “rabbit ears” are not suitable for a reliable DTV reception. You may experience blockiness, freezes and loss of signal due to the fact that rabbit ears are not optimized for the UHF DTV reception.

An outdoor antenna works the best. If that is not an option, we recommend indoor antenna that is specifically optimized for digital broadcast. The least expensive is a “Silver Sensor” type antenna, Zenith model ZHDTV1 or Philips model PHDTV1. I was unable to find those models locally, only on line. Two other models we tested are available locally at Target: Philips SDV2740/27 and MANT940.

Now about the DTV converter box: There are a number of converter boxes available locally that qualify for the $40-off coupon program, and there is a substantially larger number of the boxes available on line. How to navigate trough all the choices and make the best selection?

Many viewers trust ratings done by Consumer Reports ®. I have reviewed their converter box ratings table and found out that they neglected to rate the one thing that, in my opinion, is the most important: The “robustness” of the DTV reception. What I mean is that Consumer Reports did not seem to test how much of signal degradation the box can handle before the picture
starts breaking up.

Under ideal reception conditions, chances are that an average viewer will not be able to see an appreciable difference in the picture quality as viewed on analog television. On the other hand, when audio drops out, the picture breaks up into tiles, freezes or disappears altogether, that is painstakingly obvious.

The NTIA, US governmental entity responsible for the administration of the coupon program, issued a list of minimum performance standards for the boxes to be eligible under this program. While all makes and models supposedly meet the minimum performance standards, one manufacturer, Zenith and its parent company, LG Electronics, makes a DTV decoder chip, the heart of the DTV converter box, which far exceeds the minimum standards.

Zenith that holds the patent to the US DTV transmission standard has been a pioneer in development of the DTV decoder chips from the beginning and put considerable resources in the research and development. Their latest 6th generation decoder chip has the best immunity to multipath interference, or “ghosts”, caused by reflections of the RF signals from various objects. It is the presence of ghosts, not the low signal strength, which is responsible for the converter boxes to fail the DTV reception.

6th generation LG chips are used in Zenith model DTT-901, available locally from Circuit City and some Radio Shack stores, and from Best Buy under the store brand Insignia model NS-DXA1.