Digital TV: Charles W. Rhodes

Charlie Rhodes is a consultant in the field of television broadcast technologies and planning. He can be reached via e-mail at cwr@bootit.com.

The End of Analog Allotments

by Charles W. Rhodes, 7.23.2008

This is the first allotment table having no analog TV channel allotments; it is our future broadcasting universe. more

Addressing Interference Problems Using FAAF

by Charles W. Rhodes, 6.25.2008

In the April 2, 2008, issue of TV Technology, I proposed a solution to DTV reception problems. This proposal could address interference problems including interference from unlicensed transmitters operating on “vacant” broadcast TV channels and weak signal problems. I call this a Frequency Agile Active Filter (FAAF). more

Unmasking the Threat of Adjacent Channels

by Charles W. Rhodes, 4.02.2008

They found that signals of this form produce what amounts to co-channel interference into channel N. Take my word for it, they would also have found the same in channel N+3K. more

More Interference Due To Signal of Triplets

by Charles W. Rhodes, 2.20.2008

Had the FCC been able to anticipate this problem of receiver-generated IM3 (noise) in “vacant channels,” perhaps it could have established minimum performance standards for consumer DTV receivers. more

Troubles With Triplets Foreseen

by Charles W. Rhodes, 2.06.2008

Last month, this column covered DTV-DTV interference from one and two undesired signals. In this issue, we will address the matter of triplets of undesired DTV signals. more

Triplets: A Grave Threat to DTV Broadcasters

by Charles W. Rhodes, 1.09.2008

There are 42 symmetrical triplets in the FCC Table of Allotments, and 161 asymmetrical triplets. Of the two kinds, Murphy’s Law says that the more numerous kind are also the worst kind from an interference point of view and Professor Murphy is once again correct. more

Single Distorted DTV Signals and Pairs

by Charles W. Rhodes, 12.19.2007

While the FCC DTV channel allotment process was based on the DTV Planning Factors in OET Bulletin No. 69, those Planning Factors were based on the assumption that each DTV station might face one, but not more than one, significant source of interference, and also on the assumption that receivers would not generate third order intermodulation products (IM3) that might fall in a local channel causing co-channel interference. more

Television Signals in the Post-Transition Miami Market

by Charles W. Rhodes, 11.21.2007

Now that we pretty much know the permanent channel allotments from the 7th Report and Order and Notice of Proposed Rule Making dated October 2006, I asked my friend Louis R. du Triel Jr. to revise the data in Table D.1 of the ATSC Recommended Practice: Receiver Performance Guidelines document A/74. more

How Unlicensed Devices Could Affect Your Future

by Charles W. Rhodes, 10.17.2007

By the time you read this, the FCC is expected to propose a set of rules by which unlicensed devices will be allowed to share TV Channels 2–51. more

Concern Over Interference Continues

by Charles W. Rhodes, 8.22.2007

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

Interference by Tuner Overloading Feared Worse

by Charles W. Rhodes, 7.25.2007

The FCC Laboratory report on the interference rejection capabilities of modern DTV receivers dated March 31, brought to my attention the fact that many viewers live in relatively weak signal areas. more

FCC Report Reveals More Potential Interference

by Charles W. Rhodes, 6.27.2007

There appears to be a great euphoria among broadcasters over telecasting to pedestrians and moving vehicles with the new technologies demonstrated at NAB2007. I wouldn’t want to upset this mood, but that development may have been overtaken by events I should brief my readers about. more

Double Trouble Comes From Undesired Signals

by Charles W. Rhodes, 5.30.2007

Two more reports of laboratory testing of DTV receivers have recently been made public and the news does not portend well. more

More Examples of Interference From Unlicensed Devices

by Charles W. Rhodes, 2.21.2007

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. more

Making Room for Unlicensed Devices

by Charles W. Rhodes, 10.18.2006

The FCC has issued a timetable to authorize sharing of broadcast spectrum with unlicensed devices in the so-called "white spaces." So whether Congress passes the telecom reform act this year or not, the FCC will complete its rulemaking. more

NTIA Proposes Minimum Performance Standards

by Charles W. Rhodes, 9.20.2006

ATSC document A/74: ATSC Recommended Practice: Receiver Performance Guidelines could be the basis for National Telecommunications and Information Administration performance standards for the 10 million federally subsidized digital-to-analog converters. more

White Spaces Are There For a Reason

by Charles W. Rhodes, 7.26.2006

I have recently written about the hot topic of sharing broadcast spectrum with unlicensed devices. more

Television Reception History Repeats Itself

by Charles W. Rhodes, 5.31.2006

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. more

What Is That Noise in the White Channel?

by Charles W. Rhodes, 4.03.2006

The FCC proposes for unlicensed transmitters operating in the TV bands (Channels 4-51), a transmitter power output limit of 1 watt in the white channel for fixed facilities and 100 mW for portable facilities. more

Unlicensed Devices Could Compromise EAS

by Charles W. Rhodes, 2.22.2006

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. more