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Author Topic: "D" 13820 kHz CW 2156Z 7/29/21  (Read 1008 times)

Offline Robot Matrix

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"D" 13820 kHz CW 2156Z 7/29/21
« on: July 29, 2021, 2202 UTC »
I'm picking up "D" being transmitted over and over on or near 13820kHz. Either stops or fades out intermittently.
NESDR Mini 2, Ham It Up v1.3, end-fed 100' L and various other antennas to cover .1-1750MHz

Offline ~SIGINT~

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #1 on: July 29, 2021, 2238 UTC »
22:15 UTC - This one is interesting. It is alternating between LSB then USB for 3 x 23 ~ 28 second segments then pauses for 23 ~ 28 seconds before repeating. The duration of the segments and pauses are inconsistent but predictable.
22:40 UTC - The signal has gone off the air.

Good signal into my location. Peaking around -108 dBm (S4 ~ S5). The signal does get clobbered on occasion by a wideband UTE.




RSPduo | Barker & Williamson antenna | Toronto, Ontario Canada
« Last Edit: July 29, 2021, 2242 UTC by ~SIGINT~ »

Offline syfr

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Re: "D" 13820 kHz CW 2156Z 7/29/21
« Reply #2 on: July 30, 2021, 0024 UTC »
Now that's interesting. Was it tone modulated SSB being toggled betwen USB and LSB
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Offline ~SIGINT~

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #3 on: July 30, 2021, 0044 UTC »
Unfortunately, the station went off-air before I had the chance to record an I/Q stream for further analysis. The LSB was a little lower in aural frequency vs. the USB, a definite difference, which means that the centre frequency (CF) might be slightly off from 13820 kHz. As can be seen in the screen shot, tones were +/- 400 Hz from CF. I was listening in double sideband (DSB) mode which allowed me to demodulate both signals simultaneously. Definitely one to keep an ear on.

Heathkit

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Re: "D" 13820 kHz CW 2156Z 7/29/21
« Reply #4 on: July 30, 2021, 1457 UTC »
Same letter in both sidebands?

Hrm... I remember in the 80's hearing an odd beacon where "A" was sent in LSB and "N" in USB.

Offline ~SIGINT~

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #5 on: July 30, 2021, 2345 UTC »
I believe so, but again, I only had appox 20 minutes before it went off the air. Once I could see that there was activity on both LSB and USB, I switched the receiver to DSB at which point I would then be receiving both LSB and USB simultaneously. Will just have to wait for it to come up again for further analysis.

Offline Teotwaki

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #6 on: July 31, 2021, 1619 UTC »
Unfortunately, the station went off-air before I had the chance to record an I/Q stream for further analysis. The LSB was a little lower in aural frequency vs. the USB, a definite difference, which means that the centre frequency (CF) might be slightly off from 13820 kHz. As can be seen in the screen shot, tones were +/- 400 Hz from CF. I was listening in double sideband (DSB) mode which allowed me to demodulate both signals simultaneously. Definitely one to keep an ear on.


Screen Shot please


Lots of ways to post images in this "How To" thread: https://www.hfunderground.com/board/index.php/topic,26834.0.html
« Last Edit: July 31, 2021, 1623 UTC by Teotwaki »
Jim
NRD-525, Elecraft KX3 and Elecraft PX3 Spectrum Display
76' end fed long wire & 66' off-center fed dipole for 10/20/40 meters
Orange County, SoCal, The better half

Offline Teotwaki

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #7 on: August 01, 2021, 1535 UTC »
Jim, screen shot was already provided in Reply #1 on: 2021-07-29, 22:38:41. Make sure your browser is not blocking mix content (I.E. http/https).

As a moderator I can access individual posts as if I was the author.

If I post a picture using the image tag button to bracket the HTTPS pointer to the image stored at a genuine image hosting site (image bb) , everyone should have no trouble seeing it.

Example:




If I take just the image pointer   http://www.milspec.ca/board/img/2021-07-29_181730.png and go there I can see the image.

If I use the Image tag button and repost



I can't see it. Maybe you can because you posted the image at milspec.ca?

I think the milspec.ca site does not allow the site to be used as an image host as opposed to ibb or other sites that host images.
« Last Edit: August 01, 2021, 1554 UTC by Teotwaki »
Jim
NRD-525, Elecraft KX3 and Elecraft PX3 Spectrum Display
76' end fed long wire & 66' off-center fed dipole for 10/20/40 meters
Orange County, SoCal, The better half

Heathkit

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Re: "D" 13820 kHz CW 2156Z 7/29/21
« Reply #8 on: August 01, 2021, 1849 UTC »
I can see his image just fine, Jim  :-\

(I could see it barefoot or through any IP my VPN assigns me *shrug* )

Offline ~SIGINT~

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Re: D 13820 kHz CW 2156 UTC 29 JUL 2021
« Reply #9 on: August 01, 2021, 2142 UTC »
21:32 UTC 01 August 2021 - A strange pulsating signal in now fading in / out on the frequency. Approx 2.8 kHz wide and potentially as wide as 5.4 kHz tuned in DSB mode. The signal is currently too weak to determine the correct band edge.

22:51 UTC - Well, this one is definitely non-predictable. I have checked on it over the past week and literally have had the receiver parked on this frequency for the majority of the day and nothing. I am still receiving that strange pulsating signal, fading in and out.


RSPduo | Barker & Williamson antenna | Toronto, Ontario Canada
« Last Edit: August 01, 2021, 2255 UTC by ~SIGINT~ »

Offline Teotwaki

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Re: "D" 13820 kHz CW 2156Z 7/29/21
« Reply #10 on: August 02, 2021, 0533 UTC »
I can see his image just fine, Jim  :-\

(I could see it barefoot or through any IP my VPN assigns me *shrug* )

Chrome is doing exactly what it is supposed to do. It's not a "browser issue" when a host site has no security certificate by choice.  Also, Image BB can host images without requiring an account, password, etc. I use ImageBB's service a lot.
Jim
NRD-525, Elecraft KX3 and Elecraft PX3 Spectrum Display
76' end fed long wire & 66' off-center fed dipole for 10/20/40 meters
Orange County, SoCal, The better half

 

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