Propagation-triggered recording

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OH2BUA
Posts: 25
Joined: Mon Aug 29, 2016 8:58 am

Propagation-triggered recording

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

OH2BUA_SWL_KIT.zip
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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: 288
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: 25
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: 25
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: 25
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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