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Author Topic: DNR beacon at 13562 kHz  (Read 1987 times)

Offline Strange Beacons

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DNR beacon at 13562 kHz
« on: December 20, 2017, 1545 UTC »
While searching for signals, I discovered a new (for me, at least) pirate beacon transmitting in the ISM band. The pattern is slow CW (approximately 5-7 wpm), transmitting a series of eleven "T"s, then the letters "DSR," then followed by "DE DSR MOJAVE DESERT."

I've been checking this area of the band for over a week in order to monitor another signal that I've discovered and this one has only just appeared this evening (0430 UTC, Tuesday, 12/19/2017).

Video recording of the beacon HERE.

Curt / W9SPY
« Last Edit: December 21, 2017, 1323 UTC by ChrisSmolinski »

Offline ChrisSmolinski

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Re: Pirate beacon at 13562 kHz
« Reply #1 on: December 20, 2017, 1615 UTC »
Actually, these are not pirate beacons, they are legal. There are generous field strength limits in the ISM band.

We have an entire forum for them: https://www.hfunderground.com/board/index.php/board,35.0.html
Chris Smolinski
Westminster, MD
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Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #2 on: December 20, 2017, 1618 UTC »
Actually, these are not pirate beacons, they are legal. There are generous field strength limits in the ISM band.

We have an entire forum for them: https://www.hfunderground.com/board/index.php/board,35.0.html

Ah, OK. Thanks for the clarification. I'm new to this area of ham radio, so I wasn't sure, mainly because there wasn't a call sign ID in the signal.

Offline ChrisSmolinski

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Re: Pirate beacon at 13562 kHz
« Reply #3 on: December 20, 2017, 1725 UTC »
Sounds like you found a new beacon, with an ID of DSR.

I'll move the thread over to the 22m forum, maybe someone else can hear it.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #4 on: December 20, 2017, 1832 UTC »
Sounds like you found a new beacon, with an ID of DSR.

I'll move the thread over to the 22m forum, maybe someone else can hear it.

Excellent, thank you Chris. I've been monitoring this frequency today and the signal is not transmitting. I'll keep checking that frequency to see if/when it starts to transmit again. Could just be a night time only transmission. Fascinating area of the radio hobby, to be sure.

Curt / W9SPY

Offline Token

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Re: Pirate beacon at 13562 kHz
« Reply #5 on: December 20, 2017, 1859 UTC »
While searching for signals, I discovered a new (for me, at least) pirate beacon transmitting in the ISM band. The pattern is slow CW (approximately 5-7 wpm), transmitting a series of eleven "T"s, then the letters "DSR," then followed by "DE DSR MOJAVE DESERT."

I've been checking this area of the band for over a week in order to monitor another signal that I've discovered and this one has only just appeared this evening (0430 UTC, Tuesday, 12/19/2017).

Video recording of the beacon HERE.
 

Sounds like you found a new beacon, with an ID of DSR.
 

Check that audio again, it is sending DNR, not DSR.

Also, what you are describing as Tís are much longer than the T in DESERT, so I think those are probably long dashes or tones, not letters.

(edit)  Just played the full recording.  Looks like 11 dashes and then "DNR  DNR".  This cycle repeats 5 times, and on 5th cycle ID changes to "DE  DNR  MOJAVE DESERT".

T!
« Last Edit: December 20, 2017, 1906 UTC by Token »
T!
Mojave Desert, California USA

Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #6 on: December 20, 2017, 2150 UTC »
While searching for signals, I discovered a new (for me, at least) pirate beacon transmitting in the ISM band. The pattern is slow CW (approximately 5-7 wpm), transmitting a series of eleven "T"s, then the letters "DSR," then followed by "DE DSR MOJAVE DESERT."

I've been checking this area of the band for over a week in order to monitor another signal that I've discovered and this one has only just appeared this evening (0430 UTC, Tuesday, 12/19/2017).

Video recording of the beacon HERE.
 

Sounds like you found a new beacon, with an ID of DSR.
 

Check that audio again, it is sending DNR, not DSR.

Also, what you are describing as Tís are much longer than the T in DESERT, so I think those are probably long dashes or tones, not letters.

(edit)  Just played the full recording.  Looks like 11 dashes and then "DNR  DNR".  This cycle repeats 5 times, and on 5th cycle ID changes to "DE  DNR  MOJAVE DESERT".

T!

I appreciate your input. I was allowing FLDIGI to do all of the decoding and it showed a "T" for each dash. But what you have pointed out makes more sense.

I listened to this again via my recording and yes, it definitely is transmitting "DNR."

Thanks, Token

Curt / W9SPY

Offline Token

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Re: Pirate beacon at 13562 kHz
« Reply #7 on: December 20, 2017, 2333 UTC »
Checking my logs I have several past suspected beacons on various frequencies with the IDs DNR or DRNK, all using "MOJAVE DESERT" in the transmission somehow.  All of them have been short duration, a few days only.

(edit)  Now that I am home I can play the video in high def, could not do that from work.  I see you were on my SDR when you made the video.  I have not heard this beacon in the past when I looked in that freq range, so no idea when it showed up.  But looking right now I see it there, but a bit different than when you recorded it.

T!
« Last Edit: December 21, 2017, 0111 UTC by Token »
T!
Mojave Desert, California USA

Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #8 on: December 21, 2017, 0210 UTC »
Checking my logs I have several past suspected beacons on various frequencies with the IDs DNR or DRNK, all using "MOJAVE DESERT" in the transmission somehow.  All of them have been short duration, a few days only.

(edit)  Now that I am home I can play the video in high def, could not do that from work.  I see you were on my SDR when you made the video.  I have not heard this beacon in the past when I looked in that freq range, so no idea when it showed up.  But looking right now I see it there, but a bit different than when you recorded it.

T!

Yes, the signal is back, but this time it is transmitting 8 dashes, then DNR DNR DNR K DE DNR MOJAVE DESERT TMP 151 TMP 151 VS 04.5 VS 04.5 VB 04.9 VB 04.9 K

Listen Live Here.

Curt / W9SPY

Edit: Here is a new recording of the signal. (Recording time and date can be seen in the UTC widget running at the top right of the video screen).
« Last Edit: December 21, 2017, 0234 UTC by Strange Beacons »

Offline Token

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Re: Pirate beacon at 13562 kHz
« Reply #9 on: December 21, 2017, 0328 UTC »

Yes, the signal is back, but this time it is transmitting 8 dashes, then DNR DNR DNR K DE DNR MOJAVE DESERT TMP 151 TMP 151 VS 04.5 VS 04.5 VB 04.9 VB 04.9 K


Edit: Here is a new recording of the signal. (Recording time and date can be seen in the UTC widget running at the top right of the video screen).

In that video it sounds to me like there are 9 dashes in each set.  Then DNR DNR DNR K.  This is repeated several times and every few cycles the DNR ID is replaced by the longer DE DNR ID you quote.

But I just tuned to it myself, and now it sounds like it is doing 12 dashes per set and is much weaker than when you made your recording.

Also, in your video I noticed that the end of each dash sounds odd.

T!
T!
Mojave Desert, California USA

Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #10 on: December 21, 2017, 0335 UTC »

Yes, the signal is back, but this time it is transmitting 8 dashes, then DNR DNR DNR K DE DNR MOJAVE DESERT TMP 151 TMP 151 VS 04.5 VS 04.5 VB 04.9 VB 04.9 K


Edit: Here is a new recording of the signal. (Recording time and date can be seen in the UTC widget running at the top right of the video screen).

In that video it sounds to me like there are 9 dashes in each set.  Then DNR DNR DNR K.  This is repeated several times and every few cycles the DNR ID is replaced by the longer DE DNR ID you quote.

But I just tuned to it myself, and now it sounds like it is doing 12 dashes per set and is much weaker than when you made your recording.

Also, in your video I noticed that the end of each dash sounds odd.

T!

Your description above is exactly what I counted and noted tonight, as well as the fact that shortly after I recorded that video, band conditions seemed to have weakened the signal to the point that I was barely able to copy it. (I just tried to check again, but your SDR is full of other listeners at the moment).

You wrote: "Also, in your video I noticed that the end of each dash sounds odd."

Prior to making the recording, I zoomed way in on the signal and noticed that the dash actually curled a tiny bit at the end of the transmission, as if it was going slightly off-frequency about three quarters of the way through the dash, if that makes sense.

Curt / W9SPY

Offline Token

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Re: Pirate beacon at 13562 kHz
« Reply #11 on: December 21, 2017, 0355 UTC »

Your description above is exactly what I counted and noted tonight, as well as the fact that shortly after I recorded that video, band conditions seemed to have weakened the signal to the point that I was barely able to copy it. (I just tried to check again, but your SDR is full of other listeners at the moment).

You wrote: "Also, in your video I noticed that the end of each dash sounds odd."

Prior to making the recording, I zoomed way in on the signal and noticed that the dash actually curled a tiny bit at the end of the transmission, as if it was going slightly off-frequency about three quarters of the way through the dash, if that makes sense.

Curt / W9SPY

No, it is not curling.  Again, working from your recording because I have not caught it strong enough to look deep yet, there appears to be almost an FSK on the end of each dash.  Possibly the filter width you are using has clipped it a bit.

Here is a screen shot of an audio spectrogram from your recording.  You can see the dash is flat, but then something happens right at the end that is making sound near the  upper and lower frequencies of your filter width.


And I only hear it on the dashes, not the CW.

T!
T!
Mojave Desert, California USA

Offline Strange Beacons

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Re: Pirate beacon at 13562 kHz
« Reply #12 on: December 21, 2017, 0408 UTC »
Here is a link to a screen shot of the signal as it was sending the dashes, zoomed in as far as the SDR will allow. While I was listening to this, there was a kind of "clunk" sound right at the very end of each transmitted dash. That "clunk" seems to be represented in the image, where the signals spreads out right at the bottom of each dash (the spread appears at the top, but keeping in mind that the waterfall is scrolling downward).

Image Here.

Curt / W9SPY

Offline ChrisSmolinski

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Re: DNR beacon at 13562 kHz
« Reply #13 on: December 21, 2017, 1324 UTC »
Interesting beacon, looks like it is transmitting quite a bit of telemetry. Some voltages, and a rather high temperature  ;D

I updated the subject to reflect the beacon ID.  I'll keep and ear/eye out for this one on the east coast.
Chris Smolinski
Westminster, MD
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NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline Strange Beacons

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Re: DNR beacon at 13562 kHz
« Reply #14 on: December 21, 2017, 1443 UTC »
Interesting beacon, looks like it is transmitting quite a bit of telemetry. Some voltages, and a rather high temperature  ;D

I updated the subject to reflect the beacon ID.  I'll keep and ear/eye out for this one on the east coast.

I'm glad you changed the subject line. My geek side (roughly 85% of my being, actually) was squirming at the mischaracterization I had caused.

And I was thinking telemetry, too. But that temperature? In December? Even for the Mojave?

Curt / W9SPY