EasyPal with 4-QAM (QPSK)
Whoops, I cut off the progress bar, but it took about 3/4 the segments to successfully receive and no segment failed to decode. Previous 16-QAM transmissions only required 1/3 or so of the total segments.
Sunday, June 23, 2013
The Mighty KBC Digital Text @ 9925 kHz, 23 Jun 2013
MT63-1K with VOA intro music as co-channel interfrence
Sunday, June 16, 2013
VOA Radiogram @ 5745 kHz, 16 Jun 2013 0230 UTC
Using AMS LSB
MFSK-16 with injected co-channel noise
MFSK-16 with -6 dB attenuation and noise
MFSK-16 with -12 dB attenuation and noise, decoding errors begin to appear
MFSK-16 with noise removed and no attenuation
EasyPal image
Saturday, June 15, 2013
The Mighty KBC Digital Text @ 9925 kHz, 16 Jun 2013
Note that the PCJ Radio International test transmission, on the same frequency and time slot, was 20 S-units weaker.
PCJ Radio International Test Transmission @ 9925 kHz, 10 Jun 2013 0000 UTC
Interference in the upper sideband, so switched to AMS LSB:
Sunday, June 9, 2013
Radio Australia Radiogram @ 9580 kHz 9 Jun 2013 1230 UTC
Interference from CRI on 9570 kHz
100% decode and decent MFSK-32 image.
100% decode and decent MFSK-32 image.
PCJ Radiogram @ 9955 kHz 9 Jun 2013 0227 UTC
WRMI always drifts around 9955 kHz.
There was some fairly wide interference from a station on 9965 kHz. 100% decode anyway.
There was some fairly wide interference from a station on 9965 kHz. 100% decode anyway.
List of Mighty KBC digital text transmissions
https://soundcloud.com/swl0
There are also a couple of early VOA Radiogram episodes. I originally created this under the mistaken assumption that I could upload unlimited audio as long as I didn't exceed a monthly quota. I'm down to my last 4 minutes, so after next week's KBC transmissions I'll start uploading them to archive.org.
There are also a couple of early VOA Radiogram episodes. I originally created this under the mistaken assumption that I could upload unlimited audio as long as I didn't exceed a monthly quota. I'm down to my last 4 minutes, so after next week's KBC transmissions I'll start uploading them to archive.org.
VOA Radiogram @ 5745 kHz, 9 Jun 2013 0230 UTC
Notes:
The flmsg payload had unclosed p tags and used an invalid tag and tag sequence (</big><big style>)
During the -9 dB MFSK-16 transmission the transmitter went off air for about 10 seconds
In the -9 dB MFSK-32 transmission, there was "In a decision 5Or, Apple won a court decision that Samsung had violated several of its patents." That was the only MFSK decoding error.
MFSK-16 with song as co-channel interference
MFSK-16 -9 dB suppressed with song as co-channel interference
VOA Radiogram going off air
MFSK-32 -9 dB suppressed with song as co-channel interference
EasyPal image
Saturday, June 8, 2013
List of VOA Radiogram recordings
I had started a tumblr, but it's just more convenient to post to one place. Nevertheless, anyone interested in high SNR VOA Radiogram recordings up to now can check out http://swradiograms.tumblr.com/. Going forward, any recordings will be linked on this blog.
Monday, April 8, 2013
REE DRM @ 9630 kHz, 9 Apr 2013
So, for the record, the DRM transmission usually looks like this:
Meanwhile, the self-interference makes the SNR borderline decodeable.
Over on 11815 kHz:
We shall see if things clear up once the above goes off air.
And ... yesterday must have been a fluke.
But even after the broadcast ended, the interference remains.
A minute later it's gone.
There's just something about that transmitter.
Meanwhile, the self-interference makes the SNR borderline decodeable.
Over on 11815 kHz:
We shall see if things clear up once the above goes off air.
And ... yesterday must have been a fluke.
But even after the broadcast ended, the interference remains.
A minute later it's gone.
There's just something about that transmitter.
Sunday, April 7, 2013
REE DRM @ 9630 kHz, 8 Apr 2013
Randomly decided to listen to 9620 kHz, and noticed that the DRM signal was not there. It came and went several times, lasting no longer than a 30 seconds each time, and blasting energy all over the place, until finally at a couple minutes past 01:00 UTC...
What happened to the splatter? This is amazing. Maybe tpreitzel can stop pasting the same damn whiny message for once.
I haven't seen SNR this good out of REE in maybe ever.
Close up of REE DRM actually not clobbering REE AM for once.
I should start paying attention to REE again. I noticed that the DRM broadcast on 11815 kHz went off air before 9630 kHz came on full time. Maybe trying to broadcast two DRM signals with their antenna configuration (maybe they just use the same physical antenna) was responsible for the nasty spectral mask.
What happened to the splatter? This is amazing. Maybe tpreitzel can stop pasting the same damn whiny message for once.
I haven't seen SNR this good out of REE in maybe ever.
Close up of REE DRM actually not clobbering REE AM for once.
I should start paying attention to REE again. I noticed that the DRM broadcast on 11815 kHz went off air before 9630 kHz came on full time. Maybe trying to broadcast two DRM signals with their antenna configuration (maybe they just use the same physical antenna) was responsible for the nasty spectral mask.
Saturday, March 2, 2013
The Mighty KBC Digital Transmissions @ 7375 kHz, 3 Mar 2013
Hello Eric and KBC listeners everywhere.
Kim Andrew Elliott here, but probably not listening, because just about now I'm giving the keynote speech at the Winter SWL Fest near Philadelphia.
So would someone please record this for me?
Coming up at just before 0200 UTC, MFSK32 with images will be centered on 1000 and 2000 Hertz.
This is The Mighty KBC on 7375 kHz.
Pretty awesome reception from this new transmitter and frequency, S9+10 or greater through the whole thing, although the broadcast started late. First digital segment was perfect across MT63-1K, PSK-125R and MFSK-32. All had the above text.
The second segment was images, which is blah. You know my opinion on using a digital FSK mode to transmit an SSTV image.
The Disco Palace @ 17875 kHz, 2 Mar 2013
Apparently it came back yesterday. Word on the street is that the DRM transmitter broke. Word on the street also says that Montsinery is going to be shut down at end of month.
Anyway, they must have done something to the transmitter, because the sidebands are much better controlled. This leads to an immediate SNR gain.
SNR peaked at around 28.2 dB, probably the highest ever for TDP. There were some severe fades in the last half hour, so if I were logging for drm log plotter, it'd probably be like 99.95% or thereabouts.
Splatter begins to become noticeable when subcarriers breach -80 dBm.
Anyway, they must have done something to the transmitter, because the sidebands are much better controlled. This leads to an immediate SNR gain.
SNR peaked at around 28.2 dB, probably the highest ever for TDP. There were some severe fades in the last half hour, so if I were logging for drm log plotter, it'd probably be like 99.95% or thereabouts.
Splatter begins to become noticeable when subcarriers breach -80 dBm.
Saturday, February 23, 2013
The Mighty KBC Digital Transmissions @ 9450 kHz, 24 Feb 2013
I actually managed to reel something in at S9+10.
MFSK-16:
THE MIGHTY KBC
New frequency starting next Sunday, 3 March, 0000 to 0200 UTC...
7375 kHz
7375 kHz
Reception reports to themightykbc@gmailcom
It's missing the period after gmail, but I think this was an actual typo and not due to bit errors over the air. On the question of whether frequency of the transmission within the passband matters, for SDR's that have a pure digital path after ADC it won't, so it didn't.
MT-63 2K:
And visit kbcradio.eu
This flmsg actually failed checksum on both the simultaneous voice/data and data only transmissions. But the content came out okay.
MFSK-16:
THE MIGHTY KBC
New frequency starting next Sunday, 3 March, 0000 to 0200 UTC...
7375 kHz
7375 kHz
Reception reports to themightykbc@gmailcom
It's missing the period after gmail, but I think this was an actual typo and not due to bit errors over the air. On the question of whether frequency of the transmission within the passband matters, for SDR's that have a pure digital path after ADC it won't, so it didn't.
MT-63 2K:
THE MIGHTY KBC
New frequency for the North America broadcast at 0000-0200 UTC, beginning 3 March 2013...
7375 kHz
Via Nauen, Germany, 125 kW
Please send reception reports to themightykbc@gmail.comAnd visit kbcradio.eu
This flmsg actually failed checksum on both the simultaneous voice/data and data only transmissions. But the content came out okay.
Sunday, February 17, 2013
The Mighty KBC Digital Transmissions @ 9450 kHz, 17 Feb 2013
I don't know why, but 9450 kHz into Toronto has always been pretty lousy. I tried WebSDR once again but despite being something ridiculous like S9+50 in the first half hour, by digital time it was around S7-S8.
But for some reason, parts of the US seemed to have pretty solid reception. The following are decoded off of a recording from The SWLing Post.
Olivia 8-2K:
WORLD RADIO DAY
13 February was World Radio Day — a day to celebrate radio as a medium; to improve international cooperation between broadcasters; and to encourage major networks and community
radio alike to promote access to information and freedom of expression over the airwaves.
See more at: http://www.unesco.org/new/en/communication-and-information/events/prizes-and-celebrations/celebrations/world-radio-day/
WITH THANKS TO THE MIGHTY KBC
PSK-125R:
"Shortwave radio can provide service where other platforms such as satellite, FM or Internet are unavailable due to high cost, geographical location, lack of infrastructure, or
even during natural or man-made disasters. ... Shortwave radio ... reaches across the digital divide to the most disadvantaged and marginalised societies."
Oldrich Cip, HFCC chairman
http://j.mp/X7lh70
MFSK-32 sign off image 1:
MFSK-32 sign off image 2:
MFSK-16 sign off image:
Personally, this slow-scan stuff over MFSK is kind of pointless. If we're going to need a certain minimum of processing power to receive this stuff at all, then send the image as attachments over flmsg.
But for some reason, parts of the US seemed to have pretty solid reception. The following are decoded off of a recording from The SWLing Post.
Olivia 8-2K:
WORLD RADIO DAY
13 February was World Radio Day — a day to celebrate radio as a medium; to improve international cooperation between broadcasters; and to encourage major networks and community
radio alike to promote access to information and freedom of expression over the airwaves.
See more at: http://www.unesco.org/new/en/communication-and-information/events/prizes-and-celebrations/celebrations/world-radio-day/
WITH THANKS TO THE MIGHTY KBC
PSK-125R:
"Shortwave radio can provide service where other platforms such as satellite, FM or Internet are unavailable due to high cost, geographical location, lack of infrastructure, or
even during natural or man-made disasters. ... Shortwave radio ... reaches across the digital divide to the most disadvantaged and marginalised societies."
Oldrich Cip, HFCC chairman
http://j.mp/X7lh70
MFSK-32 sign off image 1:
MFSK-32 sign off image 2:
MFSK-16 sign off image:
Personally, this slow-scan stuff over MFSK is kind of pointless. If we're going to need a certain minimum of processing power to receive this stuff at all, then send the image as attachments over flmsg.
Saturday, February 2, 2013
The Mighty KBC Digital Transmissions @ 9450 kHz, 2 Feb 2013
A repeat from 26 Jan, which I missed.
First message:
Kim Andrew Elliott here...
Please join me at the Winter SWL Fest, March 1 and 2, Plymouth Meeting, Pennsylvania (near Philadelphia).
I will talk about transmitting digital text modes via shortwave, and demonstrate decoding.
Information at...
swlfest.com
swlfest.com
The next text transmission, just before 0200 UTC, will be in MT63-2000 (long interleave) centered on 1500Hz, and an image in MFSK16 centered on 2800 Hz.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|T|H|E| |M|I|G|H|T|Y| |K|B|C|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Second message was the same html from 13 Jan using MT63-2K. There was also an MFSK-16 image:
Received via WebSDR, S9+40 and no reception errors.
First message:
Kim Andrew Elliott here...
Please join me at the Winter SWL Fest, March 1 and 2, Plymouth Meeting, Pennsylvania (near Philadelphia).
I will talk about transmitting digital text modes via shortwave, and demonstrate decoding.
Information at...
swlfest.com
swlfest.com
The next text transmission, just before 0200 UTC, will be in MT63-2000 (long interleave) centered on 1500Hz, and an image in MFSK16 centered on 2800 Hz.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|T|H|E| |M|I|G|H|T|Y| |K|B|C|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Second message was the same html from 13 Jan using MT63-2K. There was also an MFSK-16 image:
Received via WebSDR, S9+40 and no reception errors.
Sunday, January 27, 2013
The Disco Palace DRM @ 17875 kHz, 30 Dec 2012
Apparently I never uploaded this. Better late than never, what with TDP being dead yet again this side of the world.
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