Digital TV
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.
Testing for DTV Interference
by Charles W. Rhodes, 06.22.2009
Any active device, amplifier or mixer will generate second order distortion products given that the input signal voltage overloads the active device. More...
Interference From Television Band Devices
by Charles W. Rhodes, 04.09.2009
The FCC has defined how close to, but outside of the predicted noise-limited perimeter of a station, a DTVB can be operated on the same channel as a DTV station in that community. More...
Interference to DTV Reception
by Charles W. Rhodes, 01.26.2009
The FCC prohibits fixed devices from using adjacent channels until it
has been proven to the satisfaction of the commission that spectrum sensing
has progressed to the point where the commission deems the technique to
be More...
What I Know About the Great White Spaces
by Charles W. Rhodes, 12.22.2008
Broadcasters are well aware that the spectrum of DTV transmitters extends outside of the allocated channel. They know this because the FCC has required that this out-of-channel emission be controlled with its RF mask More...
White Spaces: Myth or Reality?
by Charles W. Rhodes, 11.18.2008
In this market, all vacant channels in the high VHF and UHF bands are also adjacent channels to one or two broadcast channels. So are adjacent channels really suitable for sharing? More...
Improving a Digital EAS With the New ATSC Signal
by Charles W. Rhodes, 10.15.2008
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. More...
An Emergency Alert System for the Digital Era
by Charles W. Rhodes, 09.17.2008
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. More...
DTV Assignments May Jinx Post-Analog Reception
by Charles W. Rhodes, 09.03.2008
The DRL channels permit a "feedback" or "return" link to be established from an ENG receive-only (ENG-RO) site to an originating TV pickup station (i.e., ENG truck). This link allows automatic transmitter power control by ENG More...
The End of Analog Allotments
by Charles W. Rhodes, 07.23.2008
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, 06.25.2008
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 More...
Unmasking the Threat of Adjacent Channels
by Charles W. Rhodes, 04.02.2008
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, 02.20.2008
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, 02.06.2008
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, 01.09.2008
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 More...