The DTV tuners in some NTIA-certified converter boxes failed perf...

saying what proportion of certified boxes contain Microtune components. Microtune provides tuner chips to nine of the roughly 60 NTIA-certified boxes, a spokeswoman said. LG, Broadcom and Zoran are the three largest component suppliers for the boxes. The agency should test some of the converter boxes off the shelf to make sure they meet NTIA’s final rules, Fontaine said. It didn’t identify which boxes failed its lab tests, in a copy of the letter it made public Wednesday. Fontaine said Microtune held a Feb. 19 meeting in Japan with the manufacturer of the converter box in question and told them of the test results. “The non-compliant results observed in the boxes tested will result in loss of television reception in large areas of many metropolitan areas,” he said. “Sales of non-compliant converter boxes could mean that millions of American households that rely on over-the-air broadcasting might not be able to receive all terrestrial TV channels available in their local reception area,” he said. Those reception problems could go unnoticed until after the DTV switchover, he said. For a coupon-eligible box to gain NTIA certification for the program, a manufacturer must self-test the box to be sure it meets NTIA reception criteria. The manufacturer sends those test results and two production samples of the box to the FCC lab for verification.