Topics

PSK beacons on HF ?

Kristoff Bonne
 

Hi all,


Quick question:
Are there beacons that transmit PSK signals continuously?


I'm currently learning GNU radio, currently tutorial 7 on the GNUradio website on decoding PSK.
So it would be nice to have a real "live" PSK signal to try to decode.

So-far, I have two sources for PSK signals: the middle-frequency beacon on QO100 and FM-RDS but I also like to have some "HF" signals to look at.
I think I remembering there used amateur-radio beacons that transmit PSK signals instead of CW. Do they still exist?

Or are there other sources of PSK signals on HF that are more or less permanent to receive?




73
kristoff - ON1ARF

Ev Tupis
 

Hi Kristoff.  The PropNET.org project provided 15 years of PSK31 signals on 30 and 10 meters.  It recently shut down.  Sorry.  However...all of the propagation that it recorded over that time is still recorded and can be visualized at http://www.PropNET.org

-Ev, W2EV

On Monday, April 20, 2020, 2:38:27 PM EDT, Kristoff Bonne <kristoff@...> wrote:





Hi all,


Quick question:
Are there beacons that transmit PSK signals continuously?


I'm currently learning GNU radio, currently tutorial 7 on the GNUradio
website on decoding PSK.
So it would be nice to have a real "live" PSK signal to try to decode.

So-far, I have two sources for PSK signals: the middle-frequency beacon
on QO100 and FM-RDS but I also like to have some "HF" signals to look at.
I think I remembering there used amateur-radio beacons that transmit PSK
signals instead of CW. Do they still exist?

Or are there other sources of PSK signals on HF that are more or less
permanent to receive?




73
kristoff - ON1ARF

Kristoff Bonne
 

Hi Ev,



The question is not about the propagation data,

What I am looking for is a real HF PSK-signal to practice the PSK decoding process I learned in the GNU radio tutorial.
(see here: https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation)


Earlier, I did experiments with decoding FSK signals with GNUradio. For that, I used the RTTY transmission of the DWD at 147.3 KHz and navtex transmissions on 490 and 518 KHz as they provided almost permanent signals to do long-term tests of the decoder flowgraph.

So, now, I am looking for a equivalent PSK-signal on HF, MW of LW to learn building a PSK demodulator.





73
kristoff - ON1ARF

On 20/04/20 21:05, Ev Tupis via groups.io wrote:
Hi Kristoff.  The PropNET.org project provided 15 years of PSK31 signals on 30 and 10 meters.  It recently shut down.  Sorry.  However...all of the propagation that it recorded over that time is still recorded and can be visualized at http://www.PropNET.org

-Ev, W2EV






On Monday, April 20, 2020, 2:38:27 PM EDT, Kristoff Bonne <kristoff@...> wrote:





Hi all,


Quick question:
Are there beacons that transmit PSK signals continuously?


I'm currently learning GNU radio, currently tutorial 7 on the GNUradio
website on decoding PSK.
So it would be nice to have a real "live" PSK signal to try to decode.

So-far, I have two sources for PSK signals: the middle-frequency beacon
on QO100 and FM-RDS but I also like to have some "HF" signals to look at.
I think I remembering there used amateur-radio beacons that transmit PSK
signals instead of CW. Do they still exist?

Or are there other sources of PSK signals on HF that are more or less
permanent to receive?




73
kristoff - ON1ARF






Siegfried Jackstien
 

hmmm only for test i would use any digimode soft and "send" my own psk signal (only audio not rf)

that way you can test the decoder

or use wscgen (see picture)

that produces a test audio ... where you can add also noise ... so then testing of your decoder is possible also with noisy signal

if that works then just tune up to 20m over the day and you sure see several psk stations

dg9bfc sigi

Am 20.04.2020 um 22:00 schrieb Kristoff Bonne:

Hi Ev,



The question is not about the propagation data,

What I am looking for is a real HF PSK-signal to practice the PSK decoding process I learned in the GNU radio tutorial.
(see here: https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation)


Earlier, I did experiments with decoding FSK signals with GNUradio. For that, I used the RTTY transmission of the DWD at 147.3 KHz and navtex transmissions on 490 and 518 KHz as they provided almost permanent signals to do long-term tests of the decoder flowgraph.

So, now, I am looking for a equivalent PSK-signal on HF, MW of LW to learn building a PSK demodulator.





73
kristoff - ON1ARF


On 20/04/20 21:05, Ev Tupis via groups.io wrote:
Hi Kristoff.  The PropNET.org project provided 15 years of PSK31 signals on 30 and 10 meters.  It recently shut down.  Sorry.  However...all of the propagation that it recorded over that time is still recorded and can be visualized at http://www.PropNET.org

-Ev, W2EV






On Monday, April 20, 2020, 2:38:27 PM EDT, Kristoff Bonne <kristoff@...> wrote:





Hi all,


Quick question:
Are there beacons that transmit PSK signals continuously?


I'm currently learning GNU radio, currently tutorial 7 on the GNUradio
website on decoding PSK.
So it would be nice to have a real "live" PSK signal to try to decode.

So-far, I have two sources for PSK signals: the middle-frequency beacon
on QO100 and FM-RDS but I also like to have some "HF" signals to look at.
I think I remembering there used amateur-radio beacons that transmit PSK
signals instead of CW. Do they still exist?

Or are there other sources of PSK signals on HF that are more or less
permanent to receive?




73
kristoff - ON1ARF









Graham
 
Edited

The psk map , shows psk activity on various bands still 

Simply way could be 

Check psk map for band and qrg
Use one of the Web sdr systems
Remote tune and use the audio feed 
Record the feed on the pc

May be some jitter etc, but , generally 
The Web feed is adequate for monitoring 
Self sync systems 

73 Graham
G0nbd

KD7JYK DM09
 

"Or are there other sources of PSK signals on HF that are more or less permanent to receive?"

14,070 kHz is the 20m watering hole, I'd start there as you are likely to see hundreds, if not thousands of signals per day. A quick check of 14,070 on a portable radio in the garage yielded numerous signals heard, mid-day, in a steel and concrete building with a 36" antenna.

Tuning to this online SDR receiver as I type this, I hear several, and see about a dozen stations:

http://kphsdr.com:8073/

Also check around

1.838 MHz 160 meter <https://en.wikipedia.org/wiki/160_meter>
3.580 MHz 80 meter <https://en.wikipedia.org/wiki/80_meter>
7.035 MHz* 40 meter <https://en.wikipedia.org/wiki/40_meter> /(region <https://en.wikipedia.org/wiki/International_Amateur_Radio_Union#Regional_organisation> 3 <https://en.wikipedia.org/wiki/International_Amateur_Radio_Union#IARU_Region_3>)/

7.070 MHz* 40 meter <https://en.wikipedia.org/wiki/40_meter> /(regions <https://en.wikipedia.org/wiki/International_Amateur_Radio_Union#Regional_organisation> 1,2 <https://en.wikipedia.org/wiki/International_Amateur_Radio_Union#IARU_Regions_1>)/

10.142 MHz 30 meter <https://en.wikipedia.org/wiki/30_meter>
14.070 MHz 20 meter <https://en.wikipedia.org/wiki/20_meter>
18.097 MHz** 17 meter <https://en.wikipedia.org/wiki/17-meter_band>
21.080 MHz* 15 meter <https://en.wikipedia.org/wiki/15_meter>
24.920 MHz 12 meter <https://en.wikipedia.org/wiki/12_meter_band>
28.120 MHz 10 meter <https://en.wikipedia.org/wiki/10_meter>
50.290 MHz 6 meter <https://en.wikipedia.org/wiki/6_meter>
144.144 MHz 2 meter <https://en.wikipedia.org/wiki/2_meter>
222.07 MHz 1.25 meter <https://en.wikipedia.org/wiki/1.25_meter>
432.2 MHz 70 centimeter <https://en.wikipedia.org/wiki/70_centimeter>
909 MHz 33 centimeter <https://en.wikipedia.org/wiki/33_centimeter>

Kristoff Bonne
 

Hi Siegfried, Graham, kd9jyk, all,


First of all, my apologies for the late reply (to much to do, to little time :-) )


I did not know this tool.
I'm a linux-user but I'll try if I can get it to run anyway.


Anycase, there are PSK31 encoders available for GNU Radio so I can generate a PSK31 signal inside GNU Radio. Also, there also exists a number of 'radio-channel' block to emulate a lot of the parameters like noise, fading multipath and so on.
However, I was just interested to see how well this all stacks up in real life, hence by question here.
I'll give it a try looking for PSK signals using the RBN. (*)


The reason I preferred a beacon-signal is that is transmits fixed on one frequency and transmits always the same text.
My idea was to let the receiver and the decoder run on that frequency for several days and monitor the Bit-error-rate of the decoder over a long period with different types of radio-condition. As a beacon continuously transmits the same text, I can  make a script to determine the BER automatically which should me it more easy to find the radio-signals where the decoder went belly-up.
(Yes, I'm a bit lazy. why look for bad decoding traces manually if you can write a computer-program to do that for you :-) )




(*)
As a side-note.
About using a websdr to download audio-samples to do PSK demodulation. Currently, I do not really understand how to do this.

A PSK decoder is based on phase-information, which means that you need I/Q signals (ok, perhaps not BPSK, but surely in higher-level PSK). However, audio-files are real numbers, i.e. only contain 'I' data. . So, how does this work?
How do you convert an single-channel audio-file into I/Q data?


I read some documents that you can do this by using "resampling:, using 2 sequential samples for I and Q, then ignore the next to, to get a I/Q at 1/4 the sampling-rate. I tried to simulate that in GNUradio, but I could not get this to work. I know it must be possible as all digital-mode applications do this, using the audio-port of the PC as input, so it can be done. But how?


Perhaps somebody who knows SDR better can explain this?




73
kristoff - ON1ARF

On 21/04/2020 12:43, Siegfried Jackstien wrote:
hmmm only for test i would use any digimode soft and "send" my own psk signal (only audio not rf)

that way you can test the decoder

or use wscgen (see picture)

that produces a test audio ... where you can add also noise ... so then testing of your decoder is possible also with noisy signal

if that works then just tune up to 20m over the day and you sure see several psk stations

dg9bfc sigi

Am 20.04.2020 um 22:00 schrieb Kristoff Bonne:
Hi Ev,



The question is not about the propagation data,

What I am looking for is a real HF PSK-signal to practice the PSK decoding process I learned in the GNU radio tutorial.
(see here: https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation)


Earlier, I did experiments with decoding FSK signals with GNUradio. For that, I used the RTTY transmission of the DWD at 147.3 KHz and navtex transmissions on 490 and 518 KHz as they provided almost permanent signals to do long-term tests of the decoder flowgraph.

So, now, I am looking for a equivalent PSK-signal on HF, MW of LW to learn building a PSK demodulator.





73
kristoff - ON1ARF


On 20/04/20 21:05, Ev Tupis via groups.io wrote:
Hi Kristoff.  The PropNET.org project provided 15 years of PSK31 signals on 30 and 10 meters.  It recently shut down.  Sorry.  However...all of the propagation that it recorded over that time is still recorded and can be visualized at http://www.PropNET.org

-Ev, W2EV






On Monday, April 20, 2020, 2:38:27 PM EDT, Kristoff Bonne <kristoff@...> wrote:





Hi all,


Quick question:
Are there beacons that transmit PSK signals continuously?


I'm currently learning GNU radio, currently tutorial 7 on the GNUradio
website on decoding PSK.
So it would be nice to have a real "live" PSK signal to try to decode.

So-far, I have two sources for PSK signals: the middle-frequency beacon
on QO100 and FM-RDS but I also like to have some "HF" signals to look at.
I think I remembering there used amateur-radio beacons that transmit PSK
signals instead of CW. Do they still exist?

Or are there other sources of PSK signals on HF that are more or less
permanent to receive?




73
kristoff - ON1ARF










Graham
 

Hi Kristoff, 

Sdr,  need to take one or two steps back , 

All the Web Sdr provides is a remote tuned radio reciever   yes some have on site decoding, but , that's really a fix for modes that cannot self synchronise , and suffers  from web  delays,  

All the Web Sdr is providing, is the recovered ''audio''  stream, which in turn,  is presented to the decoding software, just the same as any sound card based data mode , the audio recovery is probably taking place in the application running on the local ''pc'' ( there are browser compatibility  issues - audio )  the Web load is reduced , the waterfall is a graphic display , the only section of spectrum conveyed , is determined by the locally selected bandwidth .

Using the audio mixer facility , in say win10,  the recovered  audio from the Web browser , may be routed to a wave recorder , data mode, speakers etc 
..your right,  live path is the best test , a well located Web Sdr,  should produce sufficient ''test data'',  you can loop 

73 Graham
G0nbd

Bo, OZ2M
 

Hi

Not exactly HF but perhaps 4 m can do? G4JNT/P http://www.g4jnt.com/SCRBG/g4jntp.html sends PSK31

Bo
www.rudius.net/oz2m :: www.rfzero.net