http://www.audiographics.com/agd/091707-1.htm
Could the cracks in the HD Radio picture be starting to show? Is there a change underway in the mindset of radio industry execs that HD Radio - as it is being positioned - is not the answer to radio's future?
Monday, September 24, 2007
Sunday, September 23, 2007
Review: Radiosophy HD100 — HD Sounds, But At What Cost?
http://blog.wired.com/gadgets/2007/08/review-radi-oso.html
Remember those crappy $15 AM/FM/cassette radios from the 80s? The HD100 looks just like one and has the sound to match. Basically a glorified clock radio, it has a chintzy, careless interface with speakers that spew a tinny unrefined sound. And while carefully tuning the HD stations results in an audible improvement over analog alternatives, the overall quality is still poor — even for a $100 device. Frankly we’d be happier keeping our money and sitting in silence.
Remember those crappy $15 AM/FM/cassette radios from the 80s? The HD100 looks just like one and has the sound to match. Basically a glorified clock radio, it has a chintzy, careless interface with speakers that spew a tinny unrefined sound. And while carefully tuning the HD stations results in an audible improvement over analog alternatives, the overall quality is still poor — even for a $100 device. Frankly we’d be happier keeping our money and sitting in silence.
Editorial on the recent approval of HD Radio (IBOC) in the USA
http://www.am-dx.com/amiboc.htm
On Thursday the 22nd of March, 2007 the Federal Communications Commission approved all facets of digital broadcasting in the USA. In particular, AM stations will soon be authorized to begin 24/7 use of their first adjacent frequencies for digital sidebands.
What this does is open the door to significant interference to all AM stations. A 50kw clear channel station can run a digital transmitter at far more power than would be authorized for any conventional station in that location on those two adjacent frequencies. It will be interesting from a rather perverse sense to see what happens at night..
I have had two HD Radios, and found that the digital signals are very fragile, and cover about half the radius (1/4 the area) of a good analog signal. Electrical noise from many sources like car ignition, light dimmers and bad wiring can easily disrupt things.
WHAT IS HD RADIO?
http://www.nautel.com/HDRadio.aspx
HD Radio is a new technology that enables AM and FM radio stations to broadcast their programs digitally, a tremendous technological leap from today's familiar analog broadcasts. These digital broadcasts provide listeners with radically improved audio quality and reception and new data services. Signal fading, static, hisses and pops are a thing of the past. Data services such as displayed song and artist information, weather and traffic alerts and much more will revolutionize the way you experience AM and FM radio. And it's all FREE for consumers, just like today's analog AM and FM radio.
HD Radio is a new technology that enables AM and FM radio stations to broadcast their programs digitally, a tremendous technological leap from today's familiar analog broadcasts. These digital broadcasts provide listeners with radically improved audio quality and reception and new data services. Signal fading, static, hisses and pops are a thing of the past. Data services such as displayed song and artist information, weather and traffic alerts and much more will revolutionize the way you experience AM and FM radio. And it's all FREE for consumers, just like today's analog AM and FM radio.
AM Stations May Be Affected by USA HD Radio--CAB
http://www.broadcastermagazine.com/issues/ISArticle.asp?id=73219&issue=09042007
As of September 14, US AM radio broadcasters that have implemented HD Radio will be allowed to transmit their digital signals at night as well as in the daytime.
Canadian AM stations operating on frequencies that are first and second-adjacent to powerful US stations may experience increased levels of skywave interference after dark as a result of this recent FCC decision.
As of September 14, US AM radio broadcasters that have implemented HD Radio will be allowed to transmit their digital signals at night as well as in the daytime.
Canadian AM stations operating on frequencies that are first and second-adjacent to powerful US stations may experience increased levels of skywave interference after dark as a result of this recent FCC decision.
AM Hybrid IBOC Parameters
http://topazdesigns.com/iboc/AM-IBOC-Parameters.html
The following technical parameters and spectrum details were gleaned from the IBOC system specifications, which are now (as of April 16, 2005) a part of the NRSC-5 IBOC Digital Radio Broadcasting standard.
The following technical parameters and spectrum details were gleaned from the IBOC system specifications, which are now (as of April 16, 2005) a part of the NRSC-5 IBOC Digital Radio Broadcasting standard.
IBOC Interference Calculations
http://topazdesigns.com/iboc/Interference-Calc.html
The procedure outlined here is intended to estimate the impact on the nighttime groundwave coverage of a Canadian AM station from a U.S. AM IBOC station located on a 1st adjacent channel. Although it is not the only situation that may cause interference, 1st adjacent IBOC is the dominant source of nighttime problems, due to the strength of nighttime skywave and the fact that most of the digital power resides in the 1st adjacent channels. Nearly all of the power that gets dumped into the adjacent channels is in the primary digital sidebands, which are located between 10 and 15 kHz from the carrier frequency of the IBOC station.
The procedure outlined here is intended to estimate the impact on the nighttime groundwave coverage of a Canadian AM station from a U.S. AM IBOC station located on a 1st adjacent channel. Although it is not the only situation that may cause interference, 1st adjacent IBOC is the dominant source of nighttime problems, due to the strength of nighttime skywave and the fact that most of the digital power resides in the 1st adjacent channels. Nearly all of the power that gets dumped into the adjacent channels is in the primary digital sidebands, which are located between 10 and 15 kHz from the carrier frequency of the IBOC station.
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