Propagation-triggered recording

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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Propagation-triggered recording

Postby OH2BUA » Fri Jan 20, 2017 4:19 pm

(Look for new fall 2017 version below...)

Hi,

i have made a set of scripts and other files which can be used to build a system which monitors JT65/JT9 (digital modes) amateur radio traffic on 160m/1.8MHz band, and if nice propagation to area you are interested in exists, a MW-BC-band recording is started. When the conditions fall off, the recording is stopped.

There is an attached zip-file containing all the necessary stuff. Sorry this is a windows thing - but easily portable also for linux. Create C:\bat\ and drop all there. Have a look, starting from README.

The default example is to start a MW-band I/Q-recording, if North American ham signals are heard - but it is fully modifiable according to your target when in comes to areas, bands, schedules etc.

The idea is that when you wake up in the morning, there might be some interesting recordings waiting for you, but ONLY IF good propagation conditions existed while you were sleeping.

Is this done a hundred times before? If old stuff, pse forget it, sorry for wasting bandwidth. If it's a new thing, let's call it OH2BUA SWL KIT.

73, Jukka oh2bua

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jon
Posts: 311
Joined: Tue Jan 06, 2015 10:48 am

Re: Propagation-triggered recording

Postby jon » Mon Jan 23, 2017 5:36 pm

I had a similar thought that you could capture CW signals on any of the HF bands and then (using CW Skimmer or similar) capture callsign prefixes (to make it simple, search and log strings immediately following ‘CQ DE’) Then with a simple look up table a programme could allow you to identify the likely origin of signals from whatever part of the world is of interest – I was thinking this could trigger an alert – but equally it could be a recording.
I really think you may have started something here, Jukka - let's see who else has thoughts on this......

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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Re: Propagation-triggered recording

Postby OH2BUA » Mon Jan 23, 2017 8:29 pm

Ok ok,

I have made some experiments with, hmm, artificial decoding of CW. When comparing JT-modes and CW as propagation indicators, I think the key differences are:

- Geographical coverage of CW is better. There is not much digital signals on 1.8MHz from let's say Northern Asia or Africa or Pacific. 7-21MHz bands are easier on this.
- JT-modes are robust and consistent. They are error-corrected, and locator squares are exchanged in every QSO, and usually also sent when calling CQ.
- In CW, a wide variety of unknown power levels are used, between 1-2000 watts. In JT, I believe most stations run between 1-10 watts.

I'm also keeping eye on NDB beacons and NAVTEX transmissions for that purpose. Hey, and then we have RDS on FM - just give us a socket to get it out from RX software for further analysis...

73, Jukka

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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Re: Propagation-triggered recording

Postby OH2BUA » Thu Feb 02, 2017 10:30 am

Hi,

here comes two oneliners. In windows-environment they need GnuWin32 Coreutils, Grep and Wget to be installed. Check your paths.

The first one kicks HDSDR I/Q-recording running, if Kyoto Real-time DST index rises to value of 10 or above:

Code: Select all

wget --no-cache -O - http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/ | grep "^.[0-9] ................................ .." | cut --output-delimiter z -c 4-7,8-11,12-15,16-19,20-23,24-27,28-31,32-35,37-40,41-44,45-48,49-52,53-56,57-60,61-64,65-68,70-73,74-77,78-81,82-85,86-89,90-93,94-97,98-101 | tr z \n | grep -v 9999 | tail -n 1 | tr -d " " | grep -q "^[1-9].$" && tasklist | grep -q HDSDR.exe || HDSDR.exe -as -recRF


The second one kills HDSDR (stops recording) , when Kyoto Real-time DST index drops below 10:

Code: Select all

wget --no-cache -O - http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/ | grep "^.[0-9] ................................ .." | cut --output-delimiter z -c 4-7,8-11,12-15,16-19,20-23,24-27,28-31,32-35,37-40,41-44,45-48,49-52,53-56,57-60,61-64,65-68,70-73,74-77,78-81,82-85,86-89,90-93,94-97,98-101 | tr z \n | grep -v 9999 | tail -n 1 | tr -d " " | grep -q "^[1-9].$" || taskkill /IM HDSDR.exe /T /F


Recommended usage: Run them at every XX:02 and XX:32 minutes while you sleep - or at least you are not operating your SDR-receiver yourself. Tune your HDSDR/ExtIO parameters carefully beforehand.

73, Jukka oh2bua

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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Re: Propagation-triggered recording

Postby OH2BUA » Wed Sep 06, 2017 6:17 am

I will release a simplified, easier to deploy version of this later in September. Based now on monitoring hugely popular FT8 mode signals on 160m/1.8MHz band.

73, Jukka

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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Re: Propagation-triggered recording

Postby OH2BUA » Wed Oct 04, 2017 6:50 am

Hi fellows,

here comes the Fall 2017 update for OH2BUA SWL Kit. It is a little bit simpler than the first version, easier to get running.

But easy thing this is not. For sure, at least some hacking is need to be done by you.

What does it do?

It monitors ham radio digital (FT8 mode) traffic on 1.8MHz (160 meters) band. If it happens to hear nice DXs, it kicks a wideband MW-recording running in purpose to capture DX broadcasts. When the FT8 DX signals disappear, it stops the recording. For me, it works overnight, every night. I'll do the harvesting next evening - IF something is recorded.

In my case, it's waiting for North American ham traffic, and aims to catch NA MW-broadcasts.

It is pretty "sensitive": If only some very weak FT8 data packets from NA are observed, and therefore a recording is made, it does not necessarily mean that stateside MW-broadcasts can be heard in the recording. (A trigger-sensitivity-filter can be added easily.)

I believe there is enough ham FT8 digital traffic for this purpose in North and South America, Europe, Middle East, East and Southeast Asia and Australia. About Africa, North Asia and Pacific - sorry, too few active stations there.

As it is only one script file (osk4_main.bat) and one configuration file (osk_squares.txt), you can edit them to fit your preferences. Your target can be something completely different than mine.

My gear is RSP2, i7 PC with SSD, Double-KAZ antenna beaming 325 degrees. Operating remote-only, server site in southern Finland, grid square KP30BX.

There are a lot of prerequisities which have to be met, or alternatively adjust the script accordingly.

README
======

Things you have to pay attention to:

1) Software which need to be installed: HDSDR 2.76, WSJT-X 1.8.0, VB-Cable (virtual audio cable), GnuWin32 Coreutils and Sed. Check that YOUR installation paths match the paths in the script. It's ok to edit the script to make them matching. GnuWin32 bin path you must have in your system PATH - edited in Control Panel ... ... ... Environment Variables. The script itself is located in C:\Osk.

2) You have to have a chain HDSDR => Virtual Audio Cable => WSJT-X working, nicely monitoring FT8 digital traffic on 1840kHz USB. Be known to where WSJT-X collects it's log, ALL.txt.

3) You need to understand how to save HDSDR preferences into "MWREC" as well as how to save WSJT-X preferences into "SDR160".

4) Understand, how to adjust HDSDR EXTIO parameters to make suitable recordings. My setup is ANT HiZ, LNA 3, IF Mode Low IF, IF Bandwidth 1.536MHz, Enable Tuner AGC Yes. LO frequency is 1200kHz. By these settings, it records the whole MW-BC band, producing about 28 gigabytes of I/Q data per hour. Have some unoccupied disk space...

5) Your target monitoring area is defined in osk_squares.txt (in C:\Osk). It is based in Maidenhead locator square system - and regexp. Pay attention to that every row starts with a single whitespace, and ends with two spaces, in purpose. By default, it is tuned for North America. If you are not familiar with locator squares, just do some googling.

6) Run the script by using Windows Task Scheduler. Starting at midnight, run every 5 minutes, repeating for 12 hours every day. Of course, you can have your own schedule... but check the script to match with it.

7) My locale is Finland. It means that at midnight Windows command "time /t" returns "00.00". Check what your system says. Time is queried twice in the script. My windows login is "OH2BUA" - i hope yours is different - check and edit the script in four rows.

8) If all this is too easy and you need even more complexity, just ask me:) Then we'll add DX-appearance checking between every minute, as well as sensitivity filter to ignore the weakest data packets.

I'll be happy to help if you meet too much troubles:).

73, Jukka
Attachments
OH2BUA_SWL_KIT_Oct_2017.zip
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OH2BUA
Posts: 41
Joined: Mon Aug 29, 2016 8:58 am

Re: Propagation-triggered recording

Postby OH2BUA » Sun Nov 05, 2017 6:12 pm

Great propagation at last night it was. Over five hours, about 130 gigabytes of I/Q recordings was caught. It contains over a hundred hours of audio from over a hundred MW AM broadcast stations to be identified :-o

Recording log is there: http://oh2bua.fi

73, Jukka

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