Digital Radio Mondiale
 

Has anybody built or bought a DRM capable receiver? I printed out a schedule
of broadcastng times from the DRM website. It appears that there are test
transmissions going on from participating broadcasters a good part of the day.
One station transmits for an hour or two and then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I mentioned in
Future of shortwave, I think there is tremendous potential for digital
shortwave particularly concerning the transmission of text. The ability to
interface these receivers with a computer (PC, laptop, palm) coupled with the
relatively high coverage to cost ratio would enable a greater variety of
thought (political, social) from marginalized groups to the reach the public.

As far as the FCC banning domestic broadcasts, the law could be challenged in
court--I admit I don't know what the cost would be. But more importantly, I
think the ban needs to be challenged in the court of public of opinion. Given
the ridiculous situation today in which businesses can own multiple stations in
one locality and enormous corporations control all the programming for those
stations the FCC's rationale for the ban falls flat on its face. Ironically,
domestic shortwave would represent the kind of programming diversity that the
FCC claims it wants to promote.

-Bill

On 22 Jan 2004 14:58:36 GMT, (Sidchase3) wrote:

Has anybody built or bought a DRM capable receiver? I printed out a schedule
of broadcastng times from the DRM website. It appears that there are test
transmissions going on from participating broadcasters a good part of the day.
One station transmits for an hour or two and then passes off to another.


I have a DRM capable system consisting of a TenTec RX-350 connected to
my computer soundcard (great receiver by the way except for the
synchronous detection). I have generally gotten excellent results
with DRM. The fidelity is probably equivelent to that of a mono FM
table radio. The big problem of course is dropouts due to ionospheric
conditions.

The transmissions directed to North America from Sackville and Bonaire
are of course always 100% listenable here in Detroit, but overseas
reception is spotty due to the fact that the signals aren't beamed
over here and they're using relatively weak transmitters for DRM.

It was a thrill to hear Radio Luxembourg back on shortwave again on
6095 using DRM toward Europe (in hi-fi stereo no-less!!!). That
station can generally be received OK on the east coast from about 0700
to 1000 UTC. BBC on 9410 is also pretty well received here in
Detroit. I've gotten Voice of Russia a few times as well in the
afternoons.

Radio Kuwait has just started Arabic broadcasts using DRM so the
technology is catching on.

I think that if Sony, Grundig, or Sangean came out with an
"all-in-one-box" DRM portable for $300 or so, that DRM could very well
bring many shortwave broadcasters (such as Radio Luxembourg) who have
abandoned the medium back to the air.

I'm really impressed with the technology, and the fact that
"high-fidelity" reception is possible on shortwave is absolutely
mind-blowing to me.

"Sidchase3" wrote in message
...
Has anybody built or bought a DRM capable receiver? I printed out a
schedule
of broadcastng times from the DRM website. It appears that there are
test
transmissions going on from participating broadcasters a good part of
the day.
One station transmits for an hour or two and then passes off to
another.

Has anyone heard these broadcasts? How was the clarity? As I mentioned
in
Future of shortwave, I think there is tremendous potential for
digital
shortwave particularly concerning the transmission of text. The
ability to
interface these receivers with a computer (PC, laptop, palm) coupled
with the
relatively high coverage to cost ratio would enable a greater variety
of
thought (political, social) from marginalized groups to the reach the
public.

Digital text transmissions are done all the time right now. Hams do it,
the military does it, utility stations do it. I suppose, if
broadcasters wanted to do it, they would. There was some thought given
to using the top 2 mhz(106 -108}of the US FM broadcast band for a
broadcast newspaper fax service. I have a 1947 magazine article showing
a prototype newspaper by radio fax service. It never caught on.

Morse code is already the simplest, lowest cost broadcast text option.

I can't see much advantage for broadcast text over text over the
internet. After all, internet text is available when the user wants it,
and not when the broadcaster wants to transmit it.


As far as the FCC banning domestic broadcasts, the law could be
challenged in
court--I admit I don't know what the cost would be. But more
importantly, I
think the ban needs to be challenged in the court of public of
opinion.

The FCC seems to have little interest in regulating speech on the
standard broadcasts, and none on SW. They certainly don't try to
enforce any distinctions between foriegn and domestic programming on SW.

The FCC does regulate frequency allocations and antenna patterns. But,
for practical purposes, when a station transmits to Mexico from Maine or
to Canada from Florida, they're also transmitting to the US.

I suppose one measure of gaugeing the interest the FCC has in
controlling what happens on shortwave radio is the low number of
enforcement actions they take against pirate broadcasters. They don't
seem to much care.

Given
the ridiculous situation today in which businesses can own multiple
stations in
one locality and enormous corporations control all the programming for
those
stations the FCC's rationale for the ban falls flat on its face.
Ironically,
domestic shortwave would represent the kind of programming diversity
that the
FCC claims it wants to promote.

-Bill

The ban isn't really enforced anymore. Several SW broadcasters sell
time for just about any kind of programming.

Frank Dresser

"Sidchase3" wrote in message
...
Has anybody built or bought a DRM capable receiver? I printed out a
schedule
of broadcastng times from the DRM website. It appears that there are test
transmissions going on from participating broadcasters a good part of the
day.
One station transmits for an hour or two and then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I mentioned in

Future of shortwave, I think there is tremendous potential for digital
shortwave particularly concerning the transmission of text. The ability to
interface these receivers with a computer (PC, laptop, palm) coupled with
the
relatively high coverage to cost ratio would enable a greater variety of
thought (political, social) from marginalized groups to the reach the
public.

I use an old Kenwood R1000 with a downconverter board to listen to DRM. When
you have a strong signal the audio quality is breathtaking for shortwave and
its amazing to hear transmissions in stereo. It doesn't take much QRM or
fading however before you get dropouts and lost audio and in practice you
need a strong signal to get reliable DRM results.

Kev

Visit http://www.radio67.freeserve.co.uk for receiver reviews.

To really make it work, they will have to have signal logging within the set,
with the transmitter routinly retransmitting
info,
so that the receiver can " toss" bad packets, or a duplicate one if the
preceeding one was sucessfully processed & wait for the next one to process.
This would cut down on fidelity, but for poor reception conditions, would make
the
" dead air" less noticeable, giving you less fidelity or no stereo or whatever
feature you toss..

( just my 2 cents worth.)




In article , "kev" writes:


I use an old Kenwood R1000 with a downconverter board to listen to DRM. When
you have a strong signal the audio quality is breathtaking for shortwave and
its amazing to hear transmissions in stereo. It doesn't take much QRM or
fading however before you get dropouts and lost audio and in practice you
need a strong signal to get reliable DRM results.

Kev

I likewise enjoy DRM on an RX-350, from Sackville and Bonaire. At times I
get no dropouts at all and it is very easy to forget one is listening to
shortwave. Music is an absolute pleasure to listen to. I'm hoping for more
transmissions and program selection, but I am sold on the technology.

Al KA5JGV
San Antonio, Tx.

But why are there no reasonably priced recievers yet?
Waiting to buy a new radio.

They are still working on the software. Just recently there was a new
release and you had to change to it, the previous release no longer works
with the new transmissions. If they released this in the firmware of a
receiver, you would most likely have to make hardware upgrades to your
receiver to keep up with it.

Al KA5JGV
San Antonio, Tx.


"N Deveau" wrote in message
...
But why are there no reasonably priced recievers yet?
Waiting to buy a new radio.

"AL KA5JGV" wrote in message
...
They are still working on the software. Just recently there was a new
release and you had to change to it, the previous release no longer works
with the new transmissions. If they released this in the firmware of a
receiver, you would most likely have to make hardware upgrades to your
receiver to keep up with it.

Al KA5JGV
San Antonio, Tx.


"N Deveau" wrote in message
...
But why are there no reasonably priced recievers yet?
Waiting to buy a new radio.



If the radio has flash memory, then no hardware upgrade would be needed.
Flash memory is cheap.

Answering the original question... Low prices come from high volume. With
the number of DRM transmissions today, it will be a while before there is
sufficient interest to create the demand. You'll have to wait a while.

Remember to when 2nd generation CD players were $600 and there were very few
CDs. Now a CD player that works as well, or better, can be found for $30.
CDs are everywhere.

The shortwave market is very small.

craigm

FJE,

SONY - Would most likely develop and design it's own Chip or
Chip Set and keep it for proprietary use only.
(This is what Sony did with AM-Stereo and AM-SYNC.)

ETON (Grundig USA) - Drake - Tecsun may outsource the work
or use what is available in the market place from OEMs.

SANGEAN - Would simply buy what is available from OEMs.

Grundig AG (Germany) - Would simply buy what is available from OEMs.

NOTE: DRM is a Licensed Technology and Products.

FWIW: There is a Digital Radio Mondiale (DRM) eGroup on YAHOO !
Digital-Radio-Mondiale-DRM-Group= http://groups.yahoo.com/group/DRM-L/


~ RHF
..
..
= = = Fredric J. Einstein
= = = wrote in message ws.com...
- - - S N I P - - -
I think that if Sony, Grundig, or Sangean came out with an
"all-in-one-box" DRM portable for $300 or so, that DRM could very well
bring many shortwave broadcasters (such as Radio Luxembourg) who have
abandoned the medium back to the air.
- - - S N I P - - -

Try WiNRADiO G303. IMHO, this is the best DRM solution money can buy,
and you also get a superb shortwave receiver. The DRM decoder is fully
integrated - which is not the case with any other existing radios:
http://www.winradio.com/home/g303-drm.htm

As to DRM clarity of reception, imagine a local FM station quality
with a shortwave broadcast 1000 miles (and more) away. It is truly
incredible, and it works.

George


On 22 Jan 2004 14:58:36 GMT, (Sidchase3) wrote:

Has anybody built or bought a DRM capable receiver? I printed out a schedule
of broadcastng times from the DRM website. It appears that there are test
transmissions going on from participating broadcasters a good part of the day.
One station transmits for an hour or two and then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I mentioned in
Future of shortwave, I think there is tremendous potential for digital
shortwave particularly concerning the transmission of text. The ability to
interface these receivers with a computer (PC, laptop, palm) coupled with the
relatively high coverage to cost ratio would enable a greater variety of
thought (political, social) from marginalized groups to the reach the public.

As far as the FCC banning domestic broadcasts, the law could be challenged in
court--I admit I don't know what the cost would be. But more importantly, I
think the ban needs to be challenged in the court of public of opinion. Given
the ridiculous situation today in which businesses can own multiple stations in
one locality and enormous corporations control all the programming for those
stations the FCC's rationale for the ban falls flat on its face. Ironically,
domestic shortwave would represent the kind of programming diversity that the
FCC claims it wants to promote.

-Bill

In article ,
(Sidchase3) wrote:

Has anybody built or bought a DRM capable receiver? I printed out a
schedule of broadcastng times from the DRM website. It appears that
there are test transmissions going on from participating broadcasters
a good part of the day. One station transmits for an hour or two and
then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I
mentioned in Future of shortwave, I think there is tremendous
potential for digital shortwave particularly concerning the
transmission of text. The ability to interface these receivers with a
computer (PC, laptop, palm) coupled with the relatively high coverage
to cost ratio would enable a greater variety of thought (political,
social) from marginalized groups to the reach the public.

As far as the FCC banning domestic broadcasts, the law could be
challenged in court--I admit I don't know what the cost would be. But
more importantly, I think the ban needs to be challenged in the
court of public of opinion. Given the ridiculous situation today in
which businesses can own multiple stations in one locality and
enormous corporations control all the programming for those stations
the FCC's rationale for the ban falls flat on its face. Ironically,
domestic shortwave would represent the kind of programming diversity
that the FCC claims it wants to promote.

I strongly disagree that DRM in its current form will create over all
improved radio reception than analog. DRM reception will be different
and could be judged "better" at times but over all different conditions
and situations reception will be no better off than analog.

Besides being no better than the current analog regime DRM brings
several new negatives along with it like some of the codexes are still
proprietary. The radios will consume more power and cost more money.

Other negatives are the ability to control where broadcasts are heard
and by whom. What is going to stop a consortium of radio manufactures
and broadcasters if the broadcasters want certain broadcasts to be
heard only on certain continents similar to what is done with DVD's as
an example of potential abuse of a digital system?

Whether anyone likes it or not the change to DRM means that shortwave
will no longer be a world wide medium.

--
Telamon
Ventura, California

On Sun, 25 Jan 2004 21:20:31 GMT, Telamon
wrote:

In article ,
(Sidchase3) wrote:

Has anybody built or bought a DRM capable receiver? I printed out a
schedule of broadcastng times from the DRM website. It appears that
there are test transmissions going on from participating broadcasters
a good part of the day. One station transmits for an hour or two and
then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I
mentioned in Future of shortwave, I think there is tremendous
potential for digital shortwave particularly concerning the
transmission of text. The ability to interface these receivers with a
computer (PC, laptop, palm) coupled with the relatively high coverage
to cost ratio would enable a greater variety of thought (political,
social) from marginalized groups to the reach the public.

As far as the FCC banning domestic broadcasts, the law could be
challenged in court--I admit I don't know what the cost would be. But
more importantly, I think the ban needs to be challenged in the
court of public of opinion. Given the ridiculous situation today in
which businesses can own multiple stations in one locality and
enormous corporations control all the programming for those stations
the FCC's rationale for the ban falls flat on its face. Ironically,
domestic shortwave would represent the kind of programming diversity
that the FCC claims it wants to promote.

I strongly disagree that DRM in its current form will create over all
improved radio reception than analog. DRM reception will be different
and could be judged "better" at times but over all different conditions
and situations reception will be no better off than analog.

I believe that DRM can never be mertely "no better than analog".
Provided you can receive the signal in the first place, you can't
possibly get the usual background noise, fading, and limited bandwidth
as you get with analog, because you re receiving an MP3 compressed
digital signal, which is practically FM broadcast quality.

On the other hand, if you can't receive the signal with the required
threshold signal-to-noise ratio, you will hear nothing. Not even
noise, just pure silence.

Besides being no better than the current analog regime DRM brings
several new negatives along with it like some of the codexes are still
proprietary. The radios will consume more power and cost more money.

If the codec is a proprietary HCMOS chip, the extra 20mA or so won't
make much difference to the battery life. With software-based PC
receivers like the Winradio G303, this point does not apply.

The cost issue will depend on economy of scale. If there are millions
of users (as DRM obviously must anticipate), the chip will cost just a
few dollars, and may also integrate other existing receiver functions,
for example a conventional AM/FM demodulator, so it won't add
significantly to the cost of the radio.

Other negatives are the ability to control where broadcasts are heard
and by whom. What is going to stop a consortium of radio manufactures
and broadcasters if the broadcasters want certain broadcasts to be
heard only on certain continents similar to what is done with DVD's as
an example of potential abuse of a digital system?

This is potentially true, but it would be much harder to police than
with DVD (where the so-called "zoning" was a failure anyway and in
most countries you now get multi-zone DVD players as a matter of
course, no questions asked).

Whether anyone likes it or not the change to DRM means that shortwave
will no longer be a world wide medium.

The DRM consorcium must make it a world-wide medium in order for the
standard to succeed in the first place.

George

I am using a custom receiver/dsp software radio that I connected using
a soundcard to the PC running Dream 1.0.

I can receive the US directed and 1 or 2 other DRM broadcasts. I had
problems with dropout prior to fully understanding the bandwidth
settings, sidebands, and signal placement in the receiver IF passband.

Overall, I am not pleased with the sound of DRM. There is an annoying
distortion related to the compression. It sounds marginally better
than internet broadcasts, if at all. I struggle to equate the sound
quality to mono FM as others due. The dynamic range and signal/noise
ratio might be there, but the objectionable artifacts (most noticeable
in speech, but masked in music) make listening tiring.

Setting aside the carrier fades, there is no comparison to analog AM
through my radio when I set the IF passband to a bandwidth around 11k.

I recommend that anyone that is considering a new receiver for DRM
purchase a bare-bones receiver with I/Q outputs and use PC based
software for decoding DRM, AM, narrow FM, sideband, and other future
digital modes. I think DRM is going to evolve.




(Sidchase3) wrote in message ...
Has anybody built or bought a DRM capable receiver? I printed out a schedule
of broadcastng times from the DRM website. It appears that there are test
transmissions going on from participating broadcasters a good part of the day.
One station transmits for an hour or two and then passes off to another.

Has anyone heard these broadcasts? How was the clarity? As I mentioned in
Future of shortwave, I think there is tremendous potential for digital
shortwave particularly concerning the transmission of text. The ability to
interface these receivers with a computer (PC, laptop, palm) coupled with the
relatively high coverage to cost ratio would enable a greater variety of
thought (political, social) from marginalized groups to the reach the public.

As far as the FCC banning domestic broadcasts, the law could be challenged in
court--I admit I don't know what the cost would be. But more importantly, I
think the ban needs to be challenged in the court of public of opinion. Given
the ridiculous situation today in which businesses can own multiple stations in
one locality and enormous corporations control all the programming for those
stations the FCC's rationale for the ban falls flat on its face. Ironically,
domestic shortwave would represent the kind of programming diversity that the
FCC claims it wants to promote.

-Bill