Reader Feedback

The value of a good engineer

Brad, I enjoyed your May editorial. You’re absolutely right: Given an intermittent that happens during air, most video engineers would just dive in and DO something (including “percussive maintenance” if that did the trick). I can personally attest to this, having held my thumb against a pinch roller for 30 minutes straight to get a videotape to play correctly. We should never lose sight of the ability to improvise in a tight spot. Wondering where my thumbprint went,

Joanne Cleveland, Ohio

DTV tuner requirements

Harry, Were the 2007 dates given in the recent “FCC Update” article on the requirement of digital tuners correct, or is that a misprint? Larry Friddle KHBS/KHOG-TV

Harry C. Martin responds: Our report in a recent issue about DTV tuner requirements was correct but, perhaps, incomplete. Indeed, 2007 is the deadline by which all TV sets, VCRs and DVD players must be equipped with DTV tuners. But, for TV sets, the requirement is phased in over five years. By July 1, 2004, 50 percent of TVs manufactured with 36-inch or larger screens must have the tuners. The requirement for equipping such large sets goes up to 100 percent as of July 1, 2005. Sets with 25- to 35-inch screens must meet the requirement by July 1, 2006. July 1, 2007, is the deadline for smaller TVs (13 to 24 inches), plus all VCRs and DVD players.

FCC proposal to allow Wi-Fi on unused TV channels

Harry, Speaking as a 35-year amateur-radio operator, I can say that this proposal is not a good idea. The potential for interference is just too great. My experience with operating amateur radio bands at 432, 903 and 1296MHz has shown that shared allocations are tricky to pull off, even with a limited number of users who understand and can tolerate the inherent interference problems. The trend in electronics for years has been to make wireless communication devices as inexpensively as possible, with minimal amounts of filtering (active or passive) to pass FCC-type acceptance rules, but just barely. A more sensible approach would be to carve out a block of contiguous channels from the current UHF spectrum and assign them solely to Wi-Fi and other wireless consumer devices (part 15, etc.) If the broadcast TV “core” shrinks to channels 2 to 51, why not assign 10MHz from about 700 to 710MHz exclusively for this purpose? This way, any potential interference would be among these restricted radiation devices, not to broadcast television at lower frequencies. Empirical studies have already shown that DTV broadcast channels can be sited closer than analog channels. In many major markets, numerous two- and three-channel groupings of sequential DTV channels are operating with little difficulty. So, reducing the core of TV channels should work to free up spectrum space. But, the addition of scattered Wi-Fi services in and amongst DTV channel allocations is a wild card in terms of interference, due to problems with intermodulation products and the varied signal levels associated with OTA DTV reception. I am concerned that constant political pressure on the FCC to free up more television spectrum for consumer electronics (and other purposes) may lead to compromises in the solid and conservative RF engineering practices the FCC has followed in the past when determining spectrum allocations. Home wireless technology is a wonderful thing, to be sure, but “cheap” and “good filtering” are not usually found in the same sentence when it comes to consumer-grade receiver design.

Pete Putman Doylestown, PA BE