DRM Reception - Pretty Nice
 

Yesterday I was listening to Radio Sweden's DRM transmission via Sackville,
NB, Canada, on 9800kHz at 2330 UTC, on my modified Ten-Tec RX-350 receiver.
The program consisted of mostly music, and I must admit, DRM is nice. The
audio quality is simply unmatched on shortwave. It was very easy to forget
that this was a shortwave transmission, it sounded like a local station. No
clicks, no pops, no qsb (fading), just very easy to listen to music.

If you get a chance to try out DRM reception, give it a shot. You will like
it. (Not affiliated with DRM in any way, just a happy listener.)

Al KA5JGV

In article ,
"AL KA5JGV" wrote:

Yesterday I was listening to Radio Sweden's DRM transmission via
Sackville, NB, Canada, on 9800kHz at 2330 UTC, on my modified Ten-Tec
RX-350 receiver. The program consisted of mostly music, and I must
admit, DRM is nice. The audio quality is simply unmatched on
shortwave. It was very easy to forget that this was a shortwave
transmission, it sounded like a local station. No clicks, no pops, no
qsb (fading), just very easy to listen to music.

If you get a chance to try out DRM reception, give it a shot. You
will like it. (Not affiliated with DRM in any way, just a happy
listener.)


I listened to a number of example recordings on the DRM website and did
not like the sound quality at all. I found voice more annoying than the
music examples. Report back when you get a chance to listen to a voice
transmission.

--
Telamon
Ventura, California

I agree with Telamon - the sound quality of DRM is terrible. If you compare
and contrast a DRM transmission from Sackville versus an analog transmission
from the same location - at the same time - analog wins.

Bob

"Telamon" wrote in message
...
In article ,
"AL KA5JGV" wrote:

Yesterday I was listening to Radio Sweden's DRM transmission via
Sackville, NB, Canada, on 9800kHz at 2330 UTC, on my modified Ten-Tec
RX-350 receiver. The program consisted of mostly music, and I must
admit, DRM is nice. The audio quality is simply unmatched on
shortwave. It was very easy to forget that this was a shortwave
transmission, it sounded like a local station. No clicks, no pops, no
qsb (fading), just very easy to listen to music.

If you get a chance to try out DRM reception, give it a shot. You
will like it. (Not affiliated with DRM in any way, just a happy
listener.)


I listened to a number of example recordings on the DRM website and did
not like the sound quality at all. I found voice more annoying than the
music examples. Report back when you get a chance to listen to a voice
transmission.

--
Telamon
Ventura, California

Al, since you are talking about modifications to the RX-350,
what have you found to be the best sources for such mods?
My internet searches have turned up nothing so far. I
wasn't researching DRM.

Thanks in advance,
Henry AC5LA


Yesterday I was listening to Radio Sweden's DRM transmission via Sackville,
NB, Canada, on 9800kHz at 2330 UTC, on my modified Ten-Tec RX-350 receiver.
The program consisted of mostly music, and I must admit, DRM is nice. The
audio quality is simply unmatched on shortwave. It was very easy to forget
that this was a shortwave transmission, it sounded like a local station. No
clicks, no pops, no qsb (fading), just very easy to listen to music.

If you get a chance to try out DRM reception, give it a shot. You will like
it. (Not affiliated with DRM in any way, just a happy listener.)

Al KA5JGV




Email address: "see_signature" - "a0015717"
Newsgroup replies may serve better the public interest.

Henry,
I wrote up a short article on the RX-350 modification. You may access it
he

http://home.satx.rr.com/ka5jgv/

This is my first shot at a web page. It also contains an article on a 4 1/2
foot loop antenna for NDB reception. Please let me know what you think. You
may also get a copy of the schematic for the RX-350 mod he

http://www.drmswr.com/receiver_mods.html

The biggest problem I find with DRM reception is a lack of choices and a
short schedule. Here in San Antonio, Tx. I get great copy from Bonaire and
good copy from Sackville. Music on DRM is excellent. You can hear every
instrument and hear it clearly. Give it a try and let me know what you
think.

Al KA5JGV


"Henry Gardiner" wrote in message
...
Al, since you are talking about modifications to the RX-350,
what have you found to be the best sources for such mods?
My internet searches have turned up nothing so far. I
wasn't researching DRM.

Thanks in advance,
Henry AC5LA

Telamon, the transmissions I listened to included voice and music and both
sounded very good. I have a problem with DRM dropouts. If you listen to a
standard shortwave transmission that fades in and out, it is acceptable and
easy to take. However on DRM a drop results in total silence. The effect is
like turning the volume control full off then back on, rapidly. Not easy to
take. But when it's on, the quality is excellent. I have been monitoring DRM
transmissions now for about 3 months and my view of them improves with time.

Al



I listened to a number of example recordings on the DRM website and did
not like the sound quality at all. I found voice more annoying than the
music examples. Report back when you get a chance to listen to a voice
transmission.

--
Telamon
Ventura, California

On Tue, 02 Dec 2003 21:17:30 GMT, "AL KA5JGV"
wrote:

Henry,
I wrote up a short article on the RX-350 modification. You may access it
he

http://home.satx.rr.com/ka5jgv/


Thanks for posting this mod Al. I just ordered a demo TenTec RX-350.
TenTec now has the RX-350D which is the exact same receiver, but with
the 12 kHz output already provided on the back panel.

I'm looking forward to this new receiver. How's the performance of
the synchronous detector?

73,

Fred E.
N8UC -- Detroit

My response/question is not intended to antagonize or troll. I would
love to purchase the TenTec DRM capable system. It's something I'd
love to "mess" with. Unfortunately (in a way), I've got broadband
Internet and with radio-locator.com I can get music/news from around
the globe. This is without drop outs, completely digital and only
some stations sound a little "phase shifty" if they stream slowly.
I've got the money for the radio but now it seems like it might be
redundant. And I can imagine, instead of fun trying to bring in a
station, it will just seem like "make work" since I can just point and
click around the globe. You know?






On Tue, 02 Dec 2003 22:11:23 GMT, Fredric J. Einstein
wrote:

On Tue, 02 Dec 2003 21:17:30 GMT, "AL KA5JGV"
wrote:

Henry,
I wrote up a short article on the RX-350 modification. You may access it
he

http://home.satx.rr.com/ka5jgv/


Thanks for posting this mod Al. I just ordered a demo TenTec RX-350.
TenTec now has the RX-350D which is the exact same receiver, but with
the 12 kHz output already provided on the back panel.

I'm looking forward to this new receiver. How's the performance of
the synchronous detector?

73,

Fred E.
N8UC -- Detroit

In article ,
"AL KA5JGV" wrote:

Telamon, the transmissions I listened to included voice and music and both
sounded very good. I have a problem with DRM dropouts. If you listen to a
standard shortwave transmission that fades in and out, it is acceptable and
easy to take. However on DRM a drop results in total silence. The effect is
like turning the volume control full off then back on, rapidly. Not easy to
take. But when it's on, the quality is excellent. I have been monitoring DRM
transmissions now for about 3 months and my view of them improves with time.

Al



I listened to a number of example recordings on the DRM website and did
not like the sound quality at all. I found voice more annoying than the
music examples. Report back when you get a chance to listen to a voice
transmission.

--
Telamon
Ventura, California

Too me the way DRM is encoded voice especially has aural artifacts that
bother me. The audio frequency response seemed to change dramatically in
the examples. At times it sounded to me like the bit rate was to low to
reproduce voice accurately similar to what streaming audio used to sound
like over the internet years ago over a dial up connection only to
change suddenly to better faster rate and then back again. I found the
effect disturbing. Also very odd shifts in volume at times occurred.

As you are finding out DRM is not going to be better then analog just
different. There will be aspects of that mode that you are going to like
better and there will be aspects that you will think worse.

If an analog signal fades you can tell what is happening is a
dynamically changing propagation effect with your ears. With DRM you
can¹t tell what is happening unless you have indicators on the radio
that would give you the status or you had equipment monitoring the
signal. Without the extra indicators you have no idea if the
interruptions in the audio are propagation, transmission problems or
your receiver. Your receiver (computer actually in your case) needs to
lock to the DRM data stream. How do you know whether your drop out
problem isn¹t because an interfering signal is confusing the decoder
causing it to lose lock on the stream? Does the software tell you?

--
Telamon
Ventura, California

"Telamon" wrote in message
news:telamon_spamshield- Too me the way DRM is encoded voice especially has
aural artifacts that
bother me. The audio frequency response seemed to change dramatically in
the examples. At times it sounded to me like the bit rate was to low to
reproduce voice accurately similar to what streaming audio used to sound
like over the internet years ago over a dial up connection only to
change suddenly to better faster rate and then back again. I found the
effect disturbing. Also very odd shifts in volume at times occurred.
Telamon
Ventura, California

Interesting observations Telamon. I will specifically look for this in the
future. Thanks.

Al

"BD" wrote in message
...

My response/question is not intended to antagonize or troll. I would
love to purchase the TenTec DRM capable system. It's something I'd
love to "mess" with. Unfortunately (in a way), I've got broadband
Internet and with radio-locator.com I can get music/news from around
the globe. This is without drop outs, completely digital and only
some stations sound a little "phase shifty" if they stream slowly.
I've got the money for the radio but now it seems like it might be
redundant. And I can imagine, instead of fun trying to bring in a
station, it will just seem like "make work" since I can just point and
click around the globe. You know?

Unless you're in the market for a new receiver, I would not purchase the
RX-350 strictly for DRM reception. The receiver needs to appeal to you for
other reasons as well. If you buy it just for DRM, you will be disappointed
by the few DRM stations available. I just dabble with DRM because it's there
and because I can.

I agree with you about the Internet. I like to listen to Polish broadcasts
via the Internet and there are many from Poland to choose from. The
reception is, for the most part, good to very good. I believe the shortwave
medium is dying and being replaced by the Internet and satellite
transmissions.

Al

... I'm looking forward to this new receiver. How's the performance of
the synchronous detector?

73,

Fred E.
N8UC -- Detroit

Fred, I didn't see a response from Al on this, so I'll take
a stab...
The synchronous detector in my recently-arrived and
updated RX-350D stays in lock until it's faced with a good
jolt of static like from thunderstorms a few hundred miles
away. It also decides that it has lost lock during
significant fades. It works better during fading with the
AGC speed set to Medium rather than Slow, and better yet
with AGC set to Fast. The synchronous detector also works
better if the radio is tuned accurately to the station's
frequency. To do that, I use the 1 Hz tuning resolution as
I switch from lower side-band to upper and back, tuning for
the same pitch on the audio components of the AM signal.
Then I try the synchronous detector again. Or I just leave
it in sideband mode.
When the synchronous detector loses sync, the receiver
apparently reverts to AM mode with a click, a change of
audio level and a change in the audio frequency response.
Then the synchronous detector will reaquire the signal and
go back to the initial set of audio conditions. This
switching is quite intrusive.
So when the going gets tough, I just use the upper or
lower sideband mode. The carrier injection of this mode is
totally reliable since it is locked to a crystal in the
receiver. It also allows the use of the auto-null filter on
strong heterodynes whereas the synchronous detector disables
the null filter. The sideband modes don't boost the low
audio frequencies like the synchronous detector does.
The sideband modes are my preferred modes for marginal
AM signals. These modes behave nicely. The only downside
is the task of getting the receiver tuned exactly on
frequency. Come to think of it, I use the synchronous or AM
detector when tuning through the broadcast bands to avoid
the heterodynes. When I find a marginal signal that I want
to monitor, I'll switch to the sideband modes.
A couple days ago I ran across some marginal 'pirate'
station transmitting on 10253.250 kHz who was on a VFO and
was drifting +/- 500 Hz. It was necessary to chase him with
the frequency knob. This was one rare occasion where a
better implementation of the synchronous detector would have
helped.
I would say that if you're not listening to shortwave
primarily for non-DRM music that you ought to ignore the
synchronous detector issue.

Greetings,
Henry AC5LA



Email address: "see_signature" - "a0015717"
Newsgroup replies may serve better the public interest.

On Wed, 03 Dec 2003 18:16:33 GMT, (Henry
Gardiner) wrote:

... I'm looking forward to this new receiver. How's the performance of
the synchronous detector?

73,

Fred E.
N8UC -- Detroit

Fred, I didn't see a response from Al on this, so I'll take
a stab...

Thanks for the advice Henry. I have a Sherwood SE-3 Synchronous
Detector hooked to a Yaesu Trancsceiver which gives absolutely
fabulous results. I guess that the only thing I can do is try the
unit out and see how it flies. Thanks again for your informed post!

Fred E.
N8UC - Detroit

In article ,
(Henry Gardiner) wrote:

snip

The only downside is the task of getting the receiver tuned exactly
on frequency.

snip

How about using the CW mode to zero beat the receiver to the station?

--
Telamon
Ventura, California

The only downside is the task of getting the receiver tuned exactly
on frequency.

snip

How about using the CW mode to zero beat the receiver to the station?

When tuned directly on frequency in the CW mode, the signal
presents itself as a 700 Hz tone. Just now I tried an
outboard 700 Hz sinewave signal to beat against this, and
indeed it is a much faster method for getting on frequency
than equating the sidebands' pitches in the two sideband
modes. Now it's easy to use those modes to listen to
correctly pitched music on the worst signals, provided the
broadcaster can maintain some frequency stability.
Thanks for the prod!
One could also use the i.f. output on the rear panel for
a similar purpose.

Henry


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