X-posted to uk.rec.audio hopefully to attract Jim Lesurf's attention.

Agamemnon wrote:
So basically everything I said was correct and you still do not have
the comprehension skills to understand it nor the courage to
apologise.


Nope, again, everything you said was incorrect.


I did find this post by yourself, though:

http://tinyurl.com/54ezs

and your (totally incorrect) assertion about MW allowing a frequency
response in the UK of 9kHz is incorrect:

Poppycock.

Look at the encoder and transmitter technical specifications

http://www.transmittersrus.com/inovo_222.htm

(pre-emphasis defeated):
"PROOF" mode: ±0.5dB, 10Hz-15kHz
222-00 (NRSC): ±1dB, 10Hz-9.7kHz
222-01 (Euro MW): ±1dB, 10Hz-8.7kHz
222-02 (US SW): ±1dB, 10Hz-6.2kHz
222-03 (Int'l SW): ±1dB, 10Hz-4.85kHz


Then they're mis-selling their product.

http://www.st-andrews.ac.uk/~www_pa/...rt9/page4.html

"The AM wave essentially carries two copies of the modulation pattern -
one in each transmission sideband. As a result, it occupies a
Transmission Bandwidth, . i.e. it takes up twice as much bandwidth as
the original information. This represents one of the main disadvantages
of AM modulation."



"MW frequency response = 50Hz-10 KHz (US) -9KHz (UK). Capable of up
to 20KHz
or better frequency response if no adjacent channels are present."

because it fails to take the double-sideband nature inherent in
envelope AM transmission.

Twaddle.

You can have virtually any frequency response you like on medium
wave. From the tech speacs above you can see that in PROOF mode its
up to 15kHz, and you can always go higher. Weather the tuner lets you
decode it is another thing. Solution. Build your own.


Broadcast MW uses envelope AM. MW receivers use envelope detectors.
Envelope AM is inherently double-sideband, so the maximum audio
bandwidth will be 4.5kHz.


Here's a recording of Radio 5 on MW, and a snapshot of the spectrum:

http://83.142.53.30/~digital/R5_MW.mp3 (1 MB)
http://www.digitalradiotech.co.uk/MW_spectrum.jpg

and the spectrum clearly shows the audio being lowpass filtered with
a stopband frequency of 4.5 kHz.

Get a proper hi-fi tuner and stop listening on a short wave radio.


The above audio was recorded from my Denon TU260L Mk1 FM/AM tuner.


I think "DAB sounds worse than FM" and all those who call me a troll
owe me an apology since I was right about the use and effect of low
pass filtering !


Yet again you've just got everything wrong so, obviously, no apology
will be forthcoming.


It is you who have got everything wrong.

I'm still waiting for your apology.


You wouldn't take the test, so I owe you no apology whatsoever, and I'd
like to know whether you've donated the agreed £10 to the Tsunami
appeal?


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

Find the cheapest Freeview, DAB & MP3 Player Prices:
http://www.digitalradiotech.co.uk/fr..._receivers.htm
http://www.digitalradiotech.co.uk/da...tal_radios.htm
http://www.digitalradiotech.co.uk/mp...rs_1GB-5GB.htm
http://www.digitalradiotech.co.uk/mp...e_capacity.htm

"DAB sounds worse than FM" wrote in message

X-posted to uk.rec.audio hopefully to attract Jim Lesurf's attention.

Agamemnon wrote:
So basically everything I said was correct and you still do not have
the comprehension skills to understand it nor the courage to
apologise.


Nope, again, everything you said was incorrect.


I did find this post by yourself, though:

http://tinyurl.com/54ezs

and your (totally incorrect) assertion about MW allowing a frequency
response in the UK of 9kHz is incorrect:

Poppycock.

Look at the encoder and transmitter technical specifications

http://www.transmittersrus.com/inovo_222.htm

(pre-emphasis defeated):
"PROOF" mode: ±0.5dB, 10Hz-15kHz
222-00 (NRSC): ±1dB, 10Hz-9.7kHz
222-01 (Euro MW): ±1dB, 10Hz-8.7kHz
222-02 (US SW): ±1dB, 10Hz-6.2kHz
222-03 (Int'l SW): ±1dB, 10Hz-4.85kHz


Then they're mis-selling their product.

http://www.st-andrews.ac.uk/~www_pa/...rt9/page4.html

"The AM wave essentially carries two copies of the modulation pattern
- one in each transmission sideband. As a result, it occupies a
Transmission Bandwidth, . i.e. it takes up twice as much bandwidth as
the original information. This represents one of the main
disadvantages of AM modulation."



"MW frequency response = 50Hz-10 KHz (US) -9KHz (UK). Capable of up
to 20KHz
or better frequency response if no adjacent channels are present."

because it fails to take the double-sideband nature inherent in
envelope AM transmission.

Twaddle.

You can have virtually any frequency response you like on medium
wave. From the tech speacs above you can see that in PROOF mode its
up to 15kHz, and you can always go higher. Weather the tuner lets you
decode it is another thing. Solution. Build your own.


Broadcast MW uses envelope AM. MW receivers use envelope detectors.
Envelope AM is inherently double-sideband, so the maximum audio
bandwidth will be 4.5kHz.


Here's a recording of Radio 5 on MW, and a snapshot of the spectrum:

http://83.142.53.30/~digital/R5_MW.mp3 (1 MB)

Got it, and Adobe audition shows the effects of a 4.5 KHz near brick-wall
filter.

http://www.digitalradiotech.co.uk/MW_spectrum.jpg

server says no such file

and the spectrum clearly shows the audio being lowpass filtered with
a stopband frequency of 4.5 kHz.

Agreed.

Get a proper hi-fi tuner and stop listening on a short wave radio.

The above audio was recorded from my Denon TU260L Mk1 FM/AM tuner.

I'd feel a little better if I knew that the 4500 Hz near brick-wall filter
your sample suggests was no way contributed to by the receiver.

Arny Krueger wrote:
"DAB sounds worse than FM" wrote in message

Here's a recording of Radio 5 on MW, and a snapshot of the
spectrum: http://83.142.53.30/~digital/R5_MW.mp3 (1 MB)

Got it, and Adobe audition shows the effects of a 4.5 KHz near
brick-wall filter.

http://www.digitalradiotech.co.uk/MW_spectrum.jpg

server says no such file



Oops, sorry, here's the correct URL:

http://www.digitalradiotech.co.uk/im...W_spectrum.jpg


and the spectrum clearly shows the audio being lowpass filtered
with a stopband frequency of 4.5 kHz.

Agreed.

Get a proper hi-fi tuner and stop listening on a short wave radio.

The above audio was recorded from my Denon TU260L Mk1 FM/AM tuner.

I'd feel a little better if I knew that the 4500 Hz near brick-wall
filter your sample suggests was no way contributed to by the receiver.


I've no idea, but I'm just going off communications theory. Here's how I
understand it: if broadcast MW stations use a channel spacing of 9kHz
(which they do in the UK), and if broadcast MW stations employ envelope
AM as their modulation scheme (which is what I've read), then the MW
stations must be bandlimited to 4.5kHz, because envelope AM is
inherently double-sideband.

And they can't use upper- or lower-sideband single-sideband modulation,
because broadcast MW receivers only use envelope detectors.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

Find the cheapest Freeview, DAB & MP3 Player Prices:
http://www.digitalradiotech.co.uk/fr..._receivers.htm
http://www.digitalradiotech.co.uk/da...tal_radios.htm
http://www.digitalradiotech.co.uk/mp...rs_1GB-5GB.htm
http://www.digitalradiotech.co.uk/mp...e_capacity.htm

"DAB sounds worse than FM" schreef in bericht
...
I'd feel a little better if I knew that the 4500 Hz near brick-wall
filter your sample suggests was no way contributed to by the receiver.


I've no idea, but I'm just going off communications theory. Here's how I
understand it: if broadcast MW stations use a channel spacing of 9kHz
(which they do in the UK), and if broadcast MW stations employ envelope
AM as their modulation scheme (which is what I've read), then the MW
stations must be bandlimited to 4.5kHz, because envelope AM is
inherently double-sideband.

That is correct in theory. In the analog days, filtering was not very steep,
so they started rolloff earlier and slided at a lower level over the 4,5 kHz
boundary. When digital filters became practical, brickwall filtering was
introduced, but in may cases well above 4,5 kHz. When the adjacent channel
is not used anywhere near, that is not a problem. But as the range on MW
increases after dark, different filter settings are used to prevent
interference to distant stations on adjacent channels.

gr, hwh

hwh wrote:
"DAB sounds worse than FM" schreef in bericht
...
I'd feel a little better if I knew that the 4500 Hz near brick-wall
filter your sample suggests was no way contributed to by the
receiver.


I've no idea, but I'm just going off communications theory. Here's
how I understand it: if broadcast MW stations use a channel spacing
of 9kHz (which they do in the UK), and if broadcast MW stations
employ envelope AM as their modulation scheme (which is what I've
read), then the MW stations must be bandlimited to 4.5kHz, because
envelope AM is inherently double-sideband.

That is correct in theory. In the analog days, filtering was not very
steep, so they started rolloff earlier and slided at a lower level
over the 4,5 kHz boundary. When digital filters became practical,
brickwall filtering was introduced, but in may cases well above 4,5
kHz. When the adjacent channel is not used anywhere near, that is not
a problem.


Sure.


But as the range on MW increases after dark, different
filter settings are used to prevent interference to distant stations
on adjacent channels.


Thanks for the confirmation.

Basically, this Agamemnon person treats laws of physics, and any other
mathematical laws as pliable and open to his own bizarre interpretation,
and all I wanted to show was that if you've got a double-sideband signal
in a 9kHz channel, then you cannot say that the audio bandwidth is 9kHz.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

Find the cheapest Freeview, DAB & MP3 Player Prices:
http://www.digitalradiotech.co.uk/fr..._receivers.htm
http://www.digitalradiotech.co.uk/da...tal_radios.htm
http://www.digitalradiotech.co.uk/mp...rs_1GB-5GB.htm
http://www.digitalradiotech.co.uk/mp...e_capacity.htm

In article , DAB sounds worse than
FM wrote:


Basically, this Agamemnon person treats laws of physics, and any other
mathematical laws as pliable and open to his own bizarre interpretation,

Can't comment on that. However I'd agree that some of the material he has
quoted seems not to be relevant to the point you make below.


and all I wanted to show was that if you've got a double-sideband
signal in a 9kHz channel, then you cannot say that the audio bandwidth
is 9kHz.

I beleive this is correct by definition with systems like simple AM due to
the required sideband symmetry.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In message , hwh
writes

"DAB sounds worse than FM" schreef in bericht
...
I'd feel a little better if I knew that the 4500 Hz near brick-wall
filter your sample suggests was no way contributed to by the receiver.


I've no idea, but I'm just going off communications theory. Here's how I
understand it: if broadcast MW stations use a channel spacing of 9kHz
(which they do in the UK), and if broadcast MW stations employ envelope
AM as their modulation scheme (which is what I've read), then the MW
stations must be bandlimited to 4.5kHz, because envelope AM is
inherently double-sideband.

That is correct in theory. In the analog days, filtering was not very steep,
so they started rolloff earlier and slided at a lower level over the 4,5 kHz
boundary. When digital filters became practical, brickwall filtering was
introduced, but in may cases well above 4,5 kHz. When the adjacent channel
is not used anywhere near, that is not a problem. But as the range on MW
increases after dark, different filter settings are used to prevent
interference to distant stations on adjacent channels.

gr, hwh



AFAIK, in Europe, MW broadcast stations still don't put anything out
above 5kHz or so. It doesn't matter how wide-band your IF strip is,
there's no more HF there to hear!
--
Chris Morriss

In the US AM broadcast stations are limited to less than
10 kHz audio bandwidth. This did not used to be true, but it is
today.

Doug McDonald

"Chris Morriss" schreef in bericht
...
AFAIK, in Europe, MW broadcast stations still don't put anything out
above 5kHz or so. It doesn't matter how wide-band your IF strip is,
there's no more HF there to hear!

Try 675 or 1008 kHz and be surprised.

gr, hwh

In message
"DAB sounds worse than FM" wrote:


I've no idea, but I'm just going off communications theory. Here's how I
understand it: if broadcast MW stations use a channel spacing of 9kHz
(which they do in the UK),

Then you're going off communications theory wrongly -- or at
least making an unjustified assumption. You seem to be confusing
audio frequency response with RF channel spacing.

And they can't use upper- or lower-sideband single-sideband modulation,
because broadcast MW receivers only use envelope detectors.

Well, I have two broadcast MW receivers here which have
synchronous demodulators, so you must be lying [sic].

--
Richard L.