HFU HF Underground

Loggings => 22 Meter Band Beacons => Topic started by: Strange Beacons on December 20, 2017, 1545 UTC

Title: DNR beacon at 13562 kHz
Post by: Strange Beacons 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 (https://youtu.be/5Bwhlm1TlDU).

Curt / W9SPY
Title: Re: Pirate beacon at 13562 kHz
Post by: ChrisSmolinski 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
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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.
Title: Re: Pirate beacon at 13562 kHz
Post by: ChrisSmolinski 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.
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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
Title: Re: Pirate beacon at 13562 kHz
Post by: Token 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 (https://youtu.be/5Bwhlm1TlDU).
 

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!
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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 (https://youtu.be/5Bwhlm1TlDU).
 

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
Title: Re: Pirate beacon at 13562 kHz
Post by: Token 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!
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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 (http://tokenradio.proxy.kiwisdr.com:8073/?f=13562.2cw).

Curt / W9SPY

Edit: Here is a new recording of the signal (https://youtu.be/pXkjjJQNQkw). (Recording time and date can be seen in the UTC widget running at the top right of the video screen).
Title: Re: Pirate beacon at 13562 kHz
Post by: Token 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 (https://youtu.be/pXkjjJQNQkw). (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!
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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 (https://youtu.be/pXkjjJQNQkw). (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
Title: Re: Pirate beacon at 13562 kHz
Post by: Token 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.
(https://a4.pbase.com/o10/50/78250/1/166741759.GoTgDNC2.DNR_dasher_13562_20171221_0218z.jpg)

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

T!
Title: Re: Pirate beacon at 13562 kHz
Post by: Strange Beacons 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 (https://imgur.com/a/66n4y).

Curt / W9SPY
Title: Re: DNR beacon at 13562 kHz
Post by: ChrisSmolinski 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.
Title: Re: DNR beacon at 13562 kHz
Post by: Strange Beacons 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
Title: Re: DNR beacon at 13562 kHz
Post by: Token on December 21, 2017, 1501 UTC
Interesting beacon, looks like it is transmitting quite a bit of telemetry. Some voltages, and a rather high temperature  ;D

Unless that is supposed to be 15.1 and the decimal point got left out.  Note that in the VS and VB there is a decimal.

This beacon is very similar to a beacon I recorded about 3 years ago.
https://www.youtube.com/watch?v=B98JUpTJDng

That one was on air for a few weeks, and I think was heard across several states.  However, I have not heard it in a long time.

T!
Title: Re: DNR beacon at 13562 kHz
Post by: Strange Beacons on December 21, 2017, 1610 UTC
Interesting beacon, looks like it is transmitting quite a bit of telemetry. Some voltages, and a rather high temperature  ;D

Unless that is supposed to be 15.1 and the decimal point got left out.  Note that in the VS and VB there is a decimal.

This beacon is very similar to a beacon I recorded about 3 years ago.
https://www.youtube.com/watch?v=B98JUpTJDng

That one was on air for a few weeks, and I think was heard across several states.  However, I have not heard it in a long time.

T!

In the description of the video that you linked to, you wrote: "The signal typically comes up after dark at my location, can be heard for an hour or two, and then slowly fades down to undetectable."

I've been monitoring this new beacon for the past few days and it is exhibiting the exact same schedule and characteristics as how you describe the DRNK beacon in your video, along with transmitting similar "telemetry" data (the most obvious similarity beyond the identifier).

Would it be a safe guess to suggest that the beacon is likely unattended, is dormant as it charges its battery via solar panel during the day, turns on at night via a light sensor, then runs until its battery starts to fade?

Curt / W9SPY
Title: Re: DNR beacon at 13562 kHz
Post by: Token on December 21, 2017, 1735 UTC

In the description of the video that you linked to, you wrote: "The signal typically comes up after dark at my location, can be heard for an hour or two, and then slowly fades down to undetectable."

I've been monitoring this new beacon for the past few days and it is exhibiting the exact same schedule and characteristics as how you describe the DRNK beacon in your video, along with transmitting similar "telemetry" data (the most obvious similarity beyond the identifier).

Would it be a safe guess to suggest that the beacon is likely unattended, is dormant as it charges its battery via solar panel during the day, turns on at night via a light sensor, then runs until its battery starts to fade?

Curt / W9SPY

In the case of DRNK the lowest battery voltage I remember it presenting was 12.8 or 12.7 (assuming the VB field was battery voltage).  If this was a lead-acid battery and VDC the battery should have been still good enough.  Also I occasionally, when conditions permitted, would catch it just before sunrise and still hear it on with good battery indications.

I always got the impression it (DRNK) was night time only, dusk to dawn, and that the fading was simply conditions.  It typically faded as the band should have been going longer, so my assumption was that the beacon was in a location where at the beginning of the night I had a good path (very little fading, almost ground wave or direct path) but then as the night progressed it skipped over me.

Not really sure how any of that would fit into DNR, even assuming they are related.  The values given in your recording for VB and VS are under 5 V.  Assuming they are real this would indicate it is not a 12 Volt battery like DRNK presumably was.  Of course, that fits.  If this is a legal beacon the low power levels required would work just fine on 5 VDC (or even 3 VDC) instead of a heavier and more expensive 12 volt lead acid battery.  I said "Assuming they are real" for a reason.  If, in your recording, VB is battery voltage and VS is solar voltage, why was the VS still so high (in your second recording) well after sundown anyplace in the contiguous US or Mexico?

T!
Title: Re: DNR beacon at 13562 kHz
Post by: Strange Beacons on December 22, 2017, 0318 UTC
I've been monitoring the DNR beacon frequency off and on since sunset today and haven't heard a single dash, nor dit/dah. Perhaps this signal has once again popped up, only to fade away again.

Curt / W9SPY
Title: Re: DNR beacon at 13562 kHz
Post by: Token on December 30, 2017, 1617 UTC
This was back on last night.  Format seems to have changed again slightly, there was more data in the CW this time.  And there is definitely something happening at the end of each dash, some kind of dual freq thing, maybe FSK.

T!