Latest articles by Charles W. Rhodes
This column has used the term “D/U ratio” (desired/ undesired) in describing how the FCC might repack the UHF TV spectrum.
You'd be amazed at what stands in the way between the viewer and the broadcast signal
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.
In the past, I have written about out-of-band (OOB) interference between ATSC signals in different bands: the low VHF band into a high VHF channel and a high VHF band ATSC into a UHF channel.
In 2014 the FCC published details on how it will configure the 600 MHz Band.
It’s a given that there is going to be considerable “channel shuffling” after the upcoming television broadcast spectrum auctions.
By now almost everyone knows the NAB has filed a lawsuit against the FCC over its spectrum auctions TV channel repack.
The most amazing finding from the FCC tests of converter boxes is the number of such toxic channel pairs there are.
All third-order intermodulation products, (IM3 and Triple Beats), occupy three contiguous channels, so there can be interference to reception on Chs. 30, 31, 32, 33, 34, and 35.
With the end of the FCC’s spectrum auction in January, it’s time to measure its damaging effects on broadcasters.
Any active device, amplifier or mixer will generate second order distortion products given that the input signal voltage overloads the active device.
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?
Distortion comes in two basic classes: Linear distortion, which is not an oxymoron; and nonlinear distortion, which includes all other distortions except noise.
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.
My research into DTV-DTV interference resulted in some interesting spectrum plots concerning third-order intermodulation (IM3) products as a source of such interference.
I replaced my 27-inch CRT receiver with a 42-inch plasma panel HDTV display more than a year ago, and I've never regretted doing so.
By all accounts, the IEEE Fall Broadcast Technology Symposium was a success.
