Charles W. Rhodes

You'd be amazed at what stands in the way between the viewer and the broadcast signal

Lagging echoes are more the serious problem

There are no minimum performance specs in the FCC rules, and in fact, the FCC does not have authority to set them.

The first time I received an e-mail about DTV reception only during daylight hours, I was dubious.

I have serious concerns about the viability of such a broadcast service.

Reducing the distances between transmitters on the same channel would increase DTV-DTV interference if each transmitter continued to operate at its present power and height of its antenna.

FMI now has three aspects.

As many DTV signals are radiated in the UHF band with more than this power, they enjoy some signal level margin within their coverage area.

Could an SFN support our ATSC standard, or would we have to change our DTV standard to embrace COFDM and thereby obsolete millions of receivers?

The FCC suggests that by adopting a Single Frequency Network topology, the present minimum distances allowed between DTV transmitters could be substantially reduced.

Since my article in the Oct. 19, 2005 issue of TV Technology, ("Developing a 24/7 Digital EAS System"), some real progress has been made by the FCC in the matter of the Emergency Alert System.

The January 1954 issue of "Proceedings of the Institute of Electrical and Electronic Engineers" was a special issue devoted entirely to the NTSC compatible color television system adopted by the FCC.

Such second-order distortion products may be generated by strong local FM radio signals in the front end of DTV receivers and downconvertors.

Our friend reminded us that the day we came was warm and sunny, and when it rains, that channel simply vanishes.

What is needed is an EAS which can alert the threatened populace while not scaring the entire nation. Our present EAS cannot do this, but a well designed Digital EAS could over our DTV channels.

The saga of the FCC Laboratories Report, “Interference Rejection Thresholds of Consumer Digital Television Receivers Available in 2005 and 2006” continues.

The IEEE Consumer Electronics Society celebrated its 75th anniversary at the International Conference on Consumer Electronics in January, along with the Consumer Electronics Show in Las Vegas.

What a DTV signal can do that an analog signal such as NTSC could not do is to awaken sleeping persons believed by the local authorities to be threatened.

Now that the FCC has established its timetable for broadcasters to elect which channel to return, I believe these same broadcasters will seek to maximize their DTV facilities.

My previous column introduced readers to a new parameter, third-order intermodulation (IM3), which is the sideband splatter from a DTV transmitter into both adjacent channels.

With the end of the FCC’s spectrum auction in January, it’s time to measure its damaging effects on broadcasters.