In article om,
Steve wrote:

On Sep 30, 5:09 pm, "David Eduardo" wrote:
"SoCal Tom" wrote in message

...



"SFTV_troy" blabbed:
... this new receiving technique would not improve the sound
(it would still be limited from 100-6000 hertz), but would only reduce
interference.

At least in the States, AM & FM broadcasting is limited to 50 Hz to 15KHz.

AM is restricted by the NRSC standard to a 10 kHz brick wall.



Digital broadcasting is limited to under 20 Hz to over 20KHz, or
basically, the extent of the normal human hearing range.

If you're listening to 100 to 6,000 Hz, you're listening to a poor
telephone connection.

Bob Orban, on the NRSC committee, found that consumer radios almost without
exception, rolled off by at least 10 db by 4.2 kHz, and passed practically
nothing over 5 kHz.

That's funny, I just asked Bob if he 'found' this and he said no way,
that you're basically just making **** up off the top of your head.

Bob didn't test all the different model radios.

--
Telamon
Ventura, California

"Telamon" wrote in message
...

That's funny, I just asked Bob if he 'found' this and he said no way,
that you're basically just making **** up off the top of your head.

Bob didn't test all the different model radios.

--
Telamon
Ventura, California

He tested enough for a reliable sample of what Americans use. I'm guessing
you don't know who Bob Orban is, so you might google him and the term
Optimod or NRSC to learn a little bit about the man who reinvented audio
processing.

Telamon wrote:


For God's sake the guy claims to be a digital engineer. Clearly he
should understand this elementary concept. You shouldn't have to explain
it to him.

This guy is no engineer. That should be obvious.

In article ,
"David Eduardo" wrote:

"Telamon" wrote in message
...

That's funny, I just asked Bob if he 'found' this and he said no way,
that you're basically just making **** up off the top of your head.

Bob didn't test all the different model radios.


He tested enough for a reliable sample of what Americans use. I'm guessing
you don't know who Bob Orban is, so you might google him and the term
Optimod or NRSC to learn a little bit about the man who reinvented audio
processing.

Yep, that where you got stuck somehow.

Reality = Take some samples + apply statistics + shake vigorously

Oops! It's not quite what you wanted. Try again.

Reality = Makeup some samples + apply statistics + shake vigorously

Looking good.

--
Telamon
Ventura, California

In article XNWLi.896$ht5.398@trnddc02,
"Earl Kiosterud" wrote:

"SFTV_troy" wrote in message
oups.com...

Earl Kiosterud wrote:

Synchronous AM demodulation uses a locally regenerated carrier,
fed along with the AM signal (upper or lower set of sidebands) to
a multiplier (modulator). The result is the audio. It replaces
the envelope (diode) detector usually used. You can think of it as
another superhet stage where the result, instead of another IF
frequency, is the baseband audio. That's because the local
oscillator is the same frequency as the carrier of the (IF)
signal, so the difference is zero. The sidebands wind up
translated to baseband audio instead of to another IF frequency.

There are advantages. Since one set of sidebands or the other can
be used, if there's a distant station 10KHz away, causing that AM
whistle, you just switch to the other set of sidebands, whichever
comes in the cleanest. Also, it doesn't depend on proper
amplitude and phase of both sets of sidebands to work properly, as
does the regular envelope detector, so it works better with
impaired signals.



I only understood about 75% of what your wrote, but if I understand
your meaning, this new receiving technique would not improve the
sound (it would still be limited from 100-6000 hertz), but would
only reduce interference.


Troy,

Well, the 6 KHz limit is due to the narrow bandwidth of the
receivers, not the detector used, or the stations. I think most AM
radios actually do much worse than that. AM radios are designed with
a limited bandpass because it gets noisy as the bandwidth goes up.
The AM band is a soup of distant stations, particularly at night, and
that's the source of much of the noise. AM radio stations in the US
are allowed up to 10 KHz audio. That's pretty listenable -- there's
only a little over a half octave to the 15 KHz limit of FM.

The synchronous detector, in addition to being able to use one set of
sidebands or the other, whichever is the best under the conditions,
is not subject to distortion from asymmetrical sidebands, such as
when there is fading, multipath, etc. There may be a non-flat audio
bandpass from those conditions, but a conventional detector will also
have distortion.

I just made a few empirical measurements on a receiver with digitally
adjustable filters and noted increased high end audio response out to
8K. 8 khz wide is not pleasing because most radio stations are
apparently boosting the high end. I usually set the bandwidth 4.4 khz
for best sound otherwise it is to sharp.

--
Telamon
Ventura, California

"Telamon" wrote in message
...
In article ,
"David Eduardo" wrote:

"Telamon" wrote in message
...

That's funny, I just asked Bob if he 'found' this and he said no way,
that you're basically just making **** up off the top of your head.

Bob didn't test all the different model radios.


He tested enough for a reliable sample of what Americans use. I'm
guessing
you don't know who Bob Orban is, so you might google him and the term
Optimod or NRSC to learn a little bit about the man who reinvented audio
processing.

Yep, that where you got stuck somehow.

Reality = Take some samples + apply statistics + shake vigorously

Oops! It's not quite what you wanted. Try again.

Reality = Makeup some samples + apply statistics + shake vigorously

Looking good.

Anyone who would question the objectivity or the ability of Bob Orban is
seriously sicko.

On Sep 30, 10:31 pm, "David Eduardo" wrote:
"Telamon" wrote in message

...





In article ,
"David Eduardo" wrote:

"Telamon" wrote in message
...

That's funny, I just asked Bob if he 'found' this and he said no way,
that you're basically just making **** up off the top of your head.

Bob didn't test all the different model radios.

He tested enough for a reliable sample of what Americans use. I'm
guessing
you don't know who Bob Orban is, so you might google him and the term
Optimod or NRSC to learn a little bit about the man who reinvented audio
processing.

Yep, that where you got stuck somehow.

Reality = Take some samples + apply statistics + shake vigorously

Oops! It's not quite what you wanted. Try again.

Reality = Makeup some samples + apply statistics + shake vigorously

Looking good.

Anyone who would question the objectivity or the ability of Bob Orban is
seriously sicko.- Hide quoted text -

- Show quoted text -

Anyone who'd falsely attribute claims to Bob Orban is even sicker.

On Sep 30, 4:50 am, SFTV_troy wrote:
I don't know much about the Satellite services, but I see sirius uses
AAC (no plus). AAC is not much better than MP3

This whole thread is disturbing for the level of misinformation within
it. Let's take these two convenient examples.

1) Sirius satellite radio uses a codec called PAC. While PAC and AAC
are both "perceptual" codecs, and while they are both rooted in some
very early Bell Labs research and patents, the two are completely
different and nowhere near compatable with each other. (XM uses a
Coding Technologies implementation of HE-AAC, trade named aacPlus.)

2) AAC is a huge leap forward from MP3 -- that's the whole point of
it. The MPEG working group was unable to improve codec technology
while staying forwards and backward compatable with MP3. So, they
started over with a clean slate. AAC (no plus) is the compression
format that iTunes uses. (The iPod plays both AAC and MP3 files, but
AAC is the preferred format.) You are free to experiment on an iPod
comparing the same material encoded to the same compression ratio
using alternately MP3 and AAC.

- Jonathan

They won't be shutting down at all. Something a lot better then IBOC
needs to come around. We all know Ibiquity is a farce.

On Sep 30, 5:18 pm, wrote:
David Eduardo wrote:
wrote in message

There are millions of obsolete televisions which will stop working in
just over a year. Does it look like the advertisers care?
They won't care about obsolete radios either.

Radio stations are not ready to go all digital, and probably will not be for
8 to 10 years.... if ever.

Both the UK and Germany have "tentatively" set 2015 as the shut-down
for FM. (They expect DAB to fill that role.) I figure the U.S.
transition will require a similar time period of fifteen years, so
sometime around 2020 will be the end of analog.

Although, I'd like to see AM die as early as 2010 since so few people
listen to it. Just make it pure digital, 10 kHz per channel.

FM can continue until 2020 (it has no interference problems).

wrote in message
ups.com...

Frank Dresser wrote:
And more expenses for the broadcaster.

They doesn't seem to be stopping them from adding second and third
channels Like WIYY in Baltimore, which has *voluntarily* added
Classic Rock and Indie Rock to their AOR primary station. Now
listeners of that style have three times as much content to enjoy.


But how is the extra programming being paid for?




Plus: If a smaller station can't afford multiple program, then they
don't need to do anything. They can just limit themselves to 1 high-
quality channel (300 kbps).

Gee, maybe if some independant station can't afford multiple programming,
they'll have even have trouble justifing buying the IBOC hardware.




Certainly not. And just because the frequency response of AM radio can
go
from 20 to 15kHz, or better doesn't mean it does. And FM radio is also
capable of excellent fidelity but it doesn't really happen either.
5.1 would be compromised in similar ways.


And then the listeners of that Classic Music station would complain,
and the manager would have to decide between (a) increasing bitrate or
(b) losing customers.

Yeah, there's a few stations in which true high fidelity sound would matter.
Not many.







People in Canada, Japan, and Australia bought AM Stereo radio in
droves. Why? Because there was a single standard, not the 4-way mess
the FCC left behind. (It's similar to today's HD DVD versus Blu-ray
battle; most people are just waiting to see who wins.)

Oh? A great many radios sold in the US are the same as the radios sold in
other countries and AM stereo still pretty rare here.


If the FCC had picked just ONE standard, then u.s. citizens would have
acted like canadians, japanese, and australians, and bought the radio
upgrade.


If they cared. The demand for AM stereo was fragile.



But with a 4-way race.... well u.s. citizens were left confused. And
it was the FCC's fault.

NOTE: This situation doesn't exist today. FCC has selected HDR, and
thus people know what they need to buy to get double or triple the #
of stations on the dial.

Yep. And HD radio is selling about as well as AM stereo did.






I already agreed with you that HQ is not going to motivate people to
upgrade. It will be seeing their favorite FM stations split into 3 or
4 programs, thus tripling their options, that will motive people to
buy.


Are they making money on the secondary channels yet? Are they even carrying
commercial advertising?


And I'm sure a fellow as clever and imaginative as you are can figure how
they might try to make money even if there aren't enough listeners to sell
commercial advertising.

Hint: They won't call it "HD radio"







In my market, Chicago, the top 2 stations account for about 10% of the
listeners. The bottom 15 on the Arbitron list draw 1% or less. And
there
are a number of stations which don't even make the list.


Hmm, interesting. In my markets (Lancaster, York, Harrisburg,
Baltimore), the listeners are fairly evenly divided bwtween the
stations. They all get a piece of the pie. See:
http://www1.arbitron.com/tlr/public/report.do


Baltimore, huh? Got any friends at ibiquity?



Actually, I just looked at the Chicago market. The ratings don't
support your claim. Even in Chicago, the listeners are fairly evenly
divided amongst the top 20 stations. (ranging from approximately 2 to
5% of the listeners, per station).

OK, I would have supported my point better if I had said:

"Many people listen to a few top rated stations, and a few people listen to
many bottom rated stations."

Either way, I'm aiming at the same point.

And my point is that there are alot of stations which don't have many
listeners, already. And HD radio does little to increase the number of
people listening to the radio.

HD radio does little to aid the health of the radio industry in general, but
it may be harmful to those people who are trying to run a small time low
profit station.


That seems to suggest listeners do what I do:

- jump from station to station
- looking for variety across multiple channels
- and that they would LOVE having 3-4 times more options on the FM
dial.


Good for you! Keep up the bandscanning!!

And if you double and redouble your efforts, you just might stumble across a
radio infomertial!!!

Frank Dresser