I recently came across an interesting article from an NAB (National
Association of Broadcasters) newsletter called "Radio TechCheck". The
article is entitled "NPR Evaluating Low Bit Radio Audio Codecs For
IBOC". You can retreive the article yourself at:

www.nab.org/scitech/techcheck/radio/rd071904.pdf

What bothers me is that this article suggest that the FM Hybrid IBOC
signal be extended beyond its current bandwith to accommodate additional
voice or data services. The diagram in this article shows the extended
hybrid portion of the IBOC signal overlapping with the current FM analog
signal. I cannot see how this could be done with some degradation to
the FM analog signal.

I'm all for new technological developments in radio but not if they
interfere with existing technology. Does anyone have further
information regarding "Extended Hybrid IBOC"?

Chris

Is it not possible that one would "replace" the other and that the
"overlap" seen on the diagram was for bandwidth illustrative purposes
only? As far as FM quality goes, it has decended rapidly over the past
few years as more radio stations have eliminated employees and hi-fi
reproduction equipment and "employed" computer software and MP3
compression. NPR in our area at least, is one of if not the only
decent sounding broadcasting station left.
-Bill
www.uptownaudio.com
Roanoke VA
(540) 343-1250

"Chris Kantack" wrote in message
...
I recently came across an interesting article from an NAB (National
Association of Broadcasters) newsletter called "Radio TechCheck".
The
article is entitled "NPR Evaluating Low Bit Radio Audio Codecs For
IBOC". You can retreive the article yourself at:

www.nab.org/scitech/techcheck/radio/rd071904.pdf

What bothers me is that this article suggest that the FM Hybrid IBOC
signal be extended beyond its current bandwith to accommodate
additional
voice or data services. The diagram in this article shows the
extended
hybrid portion of the IBOC signal overlapping with the current FM
analog
signal. I cannot see how this could be done with some degradation
to
the FM analog signal.

I'm all for new technological developments in radio but not if they
interfere with existing technology. Does anyone have further
information regarding "Extended Hybrid IBOC"?

Chris

In article , says...
Is it not possible that one would "replace" the other and that the
"overlap" seen on the diagram was for bandwidth illustrative purposes
only? As far as FM quality goes, it has decended rapidly over the past
few years as more radio stations have eliminated employees and hi-fi
reproduction equipment and "employed" computer software and MP3
compression. NPR in our area at least, is one of if not the only
decent sounding broadcasting station left.
-Bill

I wrote to John Kean (Senior Technologist of NPR), he's sent me a 10
page report today summarizing the signal-to-noise studies made regarding
Extended Hybrid Mode IBOC. Different types of radios were tested,
broken down into these categories:

Automobile
(Kenwood HR-100, Pioneer DEH-1600, Honda 39110-S01-A010-M1)

Component Receivers and Tuners
(Sony STR-DE-197, Denon TU-380RD, Denon TU-680NAB)

Compact and Portable Radios
(Aiwa XP-R600, Sony WM-FX290, Sony ICF-SW7600G, RCA RCD147,
Panasonic SC-PM19)

FM SCA Subcarrier Receivers
(McMartin SCA TR-E5, Compol SCA-8A, Norver NU-1C)

Conclusions:

Virtually no effect on automotive reception. A neglible 0.1 dB
increase in noise which is easily masked by the automotive environment.

Depending on the strength of the signal input, component receivers and
tuners experienced a negligible 0.3dB (at 60 dBu) to 1.3 dB Gaussian
noise increase (at 100 dBu). Very difficult to detect.

SCA receivers also exhibited little or no susceptibility to IBOC
Extended Hybrid Carriers.

Low cost compact (table/shelf) radios fared the worse. They averaged a
3.1 dB increase in noise with Extended Hybrid IBOC. Theory is that
these radios have lower quality IF filters and have less AM noise
rejection in their FM detectors.

I would have liked to have seen a wider sample of radios tested, but the
results are encouraging to those of us who wish to preserve the quality
of FM audio as we enter the digital age. I live near Seattle where a
number of stations are already transmitting an IBOC digital signal.
I'm happy to say that I've not been able to detect any changes in the
analog signal quality of these stations. (Of course, these stations are
not likely transmitting with the Extended Hybrid IBOC mode.)

Chris Kantack
Bellingham, WA

Yes, definitely

The most egregious attack on FM sound quality, at least here in the NYC
Metro area, is the dearth of stations (only WQXR and part time on WNYC).
WQXR is desperate for any advertisement -- if you want to hear ads for
funeral homes you'll get a good idea of what they think of their market
dynamics.

WQXR is also running with less "juice" than before -- (this was confirmed to
me by one of their engineers, it may have been temporary) -- I noticed that
the S-Level (if you can call it that, there is a signal strength meter on my
Linn) -- was down several dB. I am using a 6 element yagi tuned between
WNYC and WQXR for FM reception.

Similarly, while in Cleveland recently I noticed that WCLV or whatever they
call themselves these days, ran the same kind of commercials you hear on
talk radio.

Of course, a.m. talk radio sound quality is also lower -- and they try to
take advantage of propagation by overly reducing the power -- I have an HP
3586C measurement receiver and you can see the dBm's drop right after 6:00
pm.

my advice -- become a webonaut -- I listen to one of the Ohio stations on
the web while I do my work at the computer.

"Chris Kantack" wrote in message
...
I recently came across an interesting article from an NAB (National
Association of Broadcasters) newsletter called "Radio TechCheck". The
article is entitled "NPR Evaluating Low Bit Radio Audio Codecs For
IBOC". You can retreive the article yourself at:

www.nab.org/scitech/techcheck/radio/rd071904.pdf

What bothers me is that this article suggest that the FM Hybrid IBOC
signal be extended beyond its current bandwith to accommodate additional
voice or data services. The diagram in this article shows the extended
hybrid portion of the IBOC signal overlapping with the current FM analog
signal. I cannot see how this could be done with some degradation to
the FM analog signal.

I'm all for new technological developments in radio but not if they
interfere with existing technology. Does anyone have further
information regarding "Extended Hybrid IBOC"?

Chris

In article , says...
Yes, definitely

The most egregious attack on FM sound quality, at least here in the NYC
Metro area, is the dearth of stations (only WQXR and part time on WNYC).
WQXR is desperate for any advertisement -- if you want to hear ads for
funeral homes you'll get a good idea of what they think of their market
dynamics.

WQXR is also running with less "juice" than before -- (this was confirmed to
me by one of their engineers, it may have been temporary) -- I noticed that
the S-Level (if you can call it that, there is a signal strength meter on my
Linn) -- was down several dB. I am using a 6 element yagi tuned between
WNYC and WQXR for FM reception.

Similarly, while in Cleveland recently I noticed that WCLV or whatever they
call themselves these days, ran the same kind of commercials you hear on
talk radio.

Of course, a.m. talk radio sound quality is also lower -- and they try to
take advantage of propagation by overly reducing the power -- I have an HP
3586C measurement receiver and you can see the dBm's drop right after 6:00
pm.

my advice -- become a webonaut -- I listen to one of the Ohio stations on
the web while I do my work at the computer.

I live about 100 miles north of Seattle. I'm fortunate in that I've got
3 great classical radio services to listen to. KING-FM (98.1 Seattle),
KZAZ FM (91.7 Bellingham NPR Classical Service) and 105.7 (CBC Radio
One) transmitting from Vancouver, BC.

However, reception is not the best in the mountainous area I live in.
Quality of signal varies drastically from day-to-day. Thus I too now,
when home, mostly listen to stations via the Internet. This is
especially convenient for me as I have added a wireless hub and can plug
my wireless laptop directly into my main stereo system.

Currently my favorite sources for Internet broadcasting a

www.streamingsoundtracks.com (64 Kbit mp3Pro stream)
www.bluebeat.com (offering a number of stations
at 160Kbit or 320 Kbit data rates)

I'm especially impressed with the quality of sound from bluebeat.com.
This site is completely free, has no spyware or adware, and the high
data rates definitely make a huge difference in offering better sound
quality than all the other web services I've listened to.

Chris Kantack