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Loggings => HF Mystery Signals => Topic started by: Token on April 04, 2020, 0103 UTC

Title: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 04, 2020, 0103 UTC
This is an oddity on shortwave that I don't think I have seen before.  If it is common then somehow or another I have missed it.

About 0420 UTC, 03 April, 2020, I noticed what appeared to be a DSB transmission on 9024 kHz.  DSB is not a commonly used mode these days, so I looked a bit closer.

The signal did appear to be DSB, it also appeared to be a repeating audio loop.  About every 21.6 seconds (start to start) the loop repeated, with about 1.6 seconds pause between audio segments.  The audio was not understandable, either it was distorted, processed in some way, or encrypted.  Longer observation showed that every 11th repeated segment included a longer pause, about 3.1 seconds.  This made a repeating cycle of 11 segments about every 239.6 seconds.

Every segment transmitted appeared identical.  Just the same 21.6 second segment (time includes the audio pause) over and over, with every 11th including an increased length pause.

I have uploaded a video of this signal to my YouTube channel.  If you watch the video I include spectrograms of the audio loops, and visual comparisons of multiple examples.  I also demodulate the signal using multiple modes, USB, LSB, AM, and NFM, to show the sound in each mode.  And the last minute or so of the video is the signal demodulated with LSB in the left audio channel and USB in the right audio channel, for comparison.

Video here:
https://www.youtube.com/watch?v=axqgrSzFzG8

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 04, 2020, 2139 UTC
Sounds to me like Asian male and female voices reading news or something else, recorded and then transmitted as dsb or exalted carrier am for whatever reason. Tdoa? Jammer testing?
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Strange Beacons on April 05, 2020, 0240 UTC
Very strange indeed, and what could possibly be the purpose of such a transmission? I shared this one via my Twitter feed (https://twitter.com/StrangeBeacons/status/1246627436793602048) in the hope that one of my followers might have a clue as to what language is being spoken.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 05, 2020, 1308 UTC
Sounds to me like Asian male and female voices reading news or something else, recorded and then transmitted as dsb or exalted carrier am for whatever reason. Tdoa? Jammer testing?

I tried to TDOA the signal, however too few receivers had it with sufficient quality to get a good result.  Lots of receivers heard it, but for most it was weak enough that Kiwi TDOA was not going to work well and the results I got were all over the place, but mostly within the US, concentrating towards the south west.  I would be very careful with that possible source region though, the plots were not confidence inspiring.  Call the region a "maybe".

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 05, 2020, 1954 UTC
When I hear about sigs like this I can't help but to recall the Yosemite Sam on hf episode. Mebbe mil sigint ops training, mebbe some asshat just fooling around giving his finals a life test.

https://www.hfunderground.com/wiki/Yosemite_Sam
https://www.youtube.com/watch?v=tuEmG0Oxa2M
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 06, 2020, 0229 UTC
This signal is up again right now, 06 April, 2020, 0220 UTC.  It appears to be identical to what it was in the video I posted.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 07, 2020, 0230 UTC
Just remembered this freq is on or very near a NORAD or STRATCOM freq, one of the ZULU series mebbe, if it turns out to be soviet jammer testing or sending us a "message" it'd not surprise me. The soviets used to employ a hf jammer (one of many) created by distorting the audio of one of their home services (Радио Маяк?) or summin and blasting it all over hf.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 07, 2020, 0248 UTC
And today, 07 April, 2020, the signal cam online sometime around 0220 UTC or so, but on a different frequency.  The format, timing, apparent content is the same, however the frequency tonight is 9007 kHz.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 07, 2020, 1847 UTC
Guess who owns 9007? CANFORCE. Day pri is 11232, secondary 9007, wich becomes nite pri as I recall. If I was a soviet jammer dude, I'd def be thinkin bout using online sdrs graciously provided by the enemy country near the target area (primary rx sites) to see how effective my efforts were before open hostilities commence.





https://www.youtube.com/watch?v=1FZMCVp5wEw
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 08, 2020, 0238 UTC
Yeah, I realized who regularly occupies it, and I also checked 11232 kHz.  However, no sign of anything there.

Also, while I can buy what you are saying about testing and using remotes, why tip your hand by hitting the frequencies of interest?  Any frequency near there would tell you what you want to know, no need to hammer the exact frequency and cause the target forces to look into what and why.  And in your scenario the targets (US and Can) have the ability to know, in seconds, the approximate area of the source.  Kiwi TDOA may be iffy on the signal location, professional HF TDOA would not.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 08, 2020, 0318 UTC
Also its not like our forces don't have a cheat sheet of extra channels to use when the soviets get feisty. On why tip their hand, they have these things up and running right now with little to do, so why not play with them?
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 08, 2020, 1207 UTC
Play with the equipment I get, play with them on the target frequencies?  I don't get that, and that is the part that makes me skeptical.  It is kind of like peace time and war time modes.  For the types of signals you are talking about, and pretty much anything that emits other than standard comms (and even a little bit there), you have modes you show the enemy all the time and modes you don't show the enemy.  And various reasons, depending on what the ability is, for not showing those abilities.  One of those reasons is telling the enemy you are getting ready.

Peace time modes are the modes (frequencies, techniques, power levels, diversity capability, antenna capability, etc) that you use all the time, for testing, alignment, training, etc.  During normal testing and training you break out these modes, they typically test the system to some specific high level and they allow operator training, all without starting a war, giving the enemy (who absolutely is watching you and analyzing your actions) too much information, or tipping the enemies hand that you might be ramping up for some action.

Wartime modes are modes you break out when things go hot.  Frequency, power, antenna modes, technique, etc, these are capabilities that you have not shown the enemy you can do.  On some Russian systems some of these capabilities are activated by switches that are physically under a wired cover, so that you have to really intend to use them, and other people know, after the fact, if you have done so.

Obviously, hitting active potential enemy frequencies is not giving away too much information on technical capability.  Assuming this was / is some kind of comm jam equipment a profile / assessment of that specific equipment probably exist, including probable or known frequency range.  So the technical capability to hit these freqs would not be revealing.  However, actually hitting potential target freqs, when this is not your normal habit, is revealing.

I guess the basics of what I am saying is, you don't typically train, or test, actually hitting your real enemy targets.  And if you uncharacteristically start doing so in preparation for planned upcoming actions you alert the enemy that the punch is coming.

Not saying that your reasoning is impossible, only that I find it less likely than someone is just playing with the system.

By the way, tonight (Tuesday night local time, Wednesday morning, 08 April, UTC) the signal was up again, and back on 9024 kHz.  It ran from 0300 to 0603 UTC.  I did have a chance to grab a remote receiver in Kharbarovsk, Russia, and the signal was 10 over S9 there with little QSB.  This matches well with the more repeating TDOA plots I managed to grab Monday when the system was on.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 08, 2020, 1807 UTC
If it is soviets getting frisky, this is may be what the systems look like;
https://planesandstuff.wordpress.com/2019/09/09/murmansk-bn-hf-ew-complex/
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 13, 2020, 0542 UTC
So it turns out this signal has, apparently, typically been up on at least 2 frequencies at one time.  The other day it was on 9024 kHz and 5708 kHz at the same time, simulcast.  Tonight (13 April, 2020 UTC date), right now at 0530 UTC, it is on 9008 kHz and 9022 kHz.  The signals on 9008 and 9022 kHz are in sync, simulcast, and started at the same time.

Further, it exhibited a potentially interesting habit tonight.

The Russian operated, Asiatic sourced, numbers station V07 and M12 are both believed to be transmitted from the Kharbarovsk, Russia, area.  And TDOA cuts of this DSB signal puts it, possibly, from the same general area.  So why talk about V07 and M12?  Both of those stations have a habit, as in they do it almost every time they are on the air, of coming up 20 to 40 minutes before the first scheduled time and tuning the transmitter.  The audio they use to tune the transmitter is often the audio form a local radio station in Kharbarovsk, that was one of the ways the source location was initially suspected.

Tonight this DSB signal did exactly the same thing.  20 minutes before it came on the air on 9008 kHz a transmitter tuned up on that frequency.  The tuning signal seemed to be audio from a broadcast station.

Possibly: Strongly probable it is the same region, possibly the same location, and the operators appear to have the same operational habits.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 13, 2020, 1333 UTC
That's some great information Token and good deductive reasoning. The big questions that remain in my mind are of course, why these odd transmissions and why this particular mode?

Are there any advantages to a DSB signal other than not taking as much power as AM?


Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 13, 2020, 1350 UTC
That's some great information Token and good deductive reasoning. The big questions that remain in my mind are of course, why these odd transmissions and why this particular mode?

Are there any advantages to a DSB signal?

DSB has no real transmission advantage over SSB.  I mean it occupies twice the bandwidth for the same amount of usable information, it spreads the same power out over twice the bandwidth, meaning less power available for the same given information.  Unless you send different data on each sideband, in which case it becomes ISB, not DSB, there just really is not an operational reason to prefer DSB over SSB.

As a jammer it is twice as wide, that could be an advantage, but this signal has a significant notch in the middle (where the low frequency components of the speech would be), making it somewhat less than optimal against some kinds of signals.  Also as a jammer it does not waste energy in the carrier, so hammering an SSB signal it works fine, and hammering an AM signal it works fine.  To jam an AM signal you don't need a carrier.

The real advantage of DSB over SSB is that the circuitry can be simpler.  The hardware is cheaper and easier to make.  If you repurpose other hardware and try to send an SSB signal you can end up with DSB.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 13, 2020, 1604 UTC
Thanks for your thoughts and for finding this signal.

So looking at all the posts it looks like you heard it Monday-Thursday April 6-8
(was it on Friday too and you weren't looking for it or was it actually absent?)
Time appeared to be approx. 0220-0600 each day.

I will be watching/listening tonight!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 13, 2020, 1828 UTC
Thanks for your thoughts and for finding this signal.

So looking at all the posts it looks like you heard it Monday-Thursday April 6-8
(was it on Friday too and you weren't looking for it or was it actually absent?)
Time appeared to be approx. 0220-0600 each day.

I will be watching/listening tonight!

Those are about the core looking times, but times are variable.

I have looked and recorded spectrum for this signal almost every night since first finding it.  I did look Saturday and Sunday (UTC) and the signal was not present.  So Friday night Pacific time would be Saturday UTC.  It looks like it has been active every weekday (UTC day) at one time or another.  I actually missed it one day myself, forgot to look, but was told by someone else it was on that night.

Keep in mind it has varied the frequencies, it has not always been on 9024 kHz.  And it appears to be active on 2 frequencies at one time.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 13, 2020, 1904 UTC
Wonder if it's an fup in their patch panel?
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: tomasernesto1986 on April 15, 2020, 1210 UTC
Hi. I think this is a encrypted communication. There is a very famous Netflix's Show called La Casa de Papel (House of Paper from Spain). In season 3 they use a ham radio and they use encryptacion technology in order to avoid the police.

The reason for using an old trasmition technology is that the police can hack all new technology specially internet communication and finds where is located the trasmition but with an old radio is more difficult find it and the authority can't inhibite the signal.

Also if you use a new top technology encriptacion system and send an encrypted message it's impossible to know what are you talking about.

In this vidio minute 1:01 you can hear it actually it sounds quite the same that the oddity frequency

https://youtu.be/HrZfMcp-cKM

I also hear this transition 5/9  in San Cristobal, Venezuela.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 15, 2020, 1430 UTC
I tuned into the Khabarovsk SDR last night as I had to be up late doing some work. I checked in numerous times over the course of several hours starting around 0220 UTC but there did not appear to be any sign of the signal.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Pigmeat on April 16, 2020, 0339 UTC
When I hear about sigs like this I can't help but to recall the Yosemite Sam on hf episode. Mebbe mil sigint ops training, mebbe some asshat just fooling around giving his finals a life test.

https://www.hfunderground.com/wiki/Yosemite_Sam
https://www.youtube.com/watch?v=tuEmG0Oxa2M

"Imma gonna blast you, ya consarnd Rabbit!" LOL!

I'm not sure any of three or four Commander Bunny's at that time knew who or what the Hell that was? The guy who started calling me back after a non WBNY show w/the code the made me call it quits. Whoever it was, they were running a boatload of power. Only one govt. agency at a time,thank you
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 16, 2020, 1700 UTC
Hi. I think this is a encrypted communication.

<<<snip>>>


Initially I thought it might be encryption of some kind, it kind of sounds a bit like old voice inversion encryption.  So I ran the signal through a voice inversion decoder, and I still ended up with junk.

Of course, that does not mean it is not some other kind of encryption, or some combination of encryption techniques.

However, the data is the same every cycle.  That means if it is encrypted communications of some kind it is the same ~20 second loop, over and over for hours, with no changes.

Encrypted source or not, it still seems like a junk transmission.  The other day a different waveform showed up, it looked like Gaussian noise or possibly PSK of some kind, on the same two frequencies (9008 and 9024 kHz).  It was never really strong enough for me to do much with it, conditions were poor.  But the 2 signals started at the same time and ended at the same time, so possibly connected.  And while this possible signal was up the normal DSB was not seen.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Rizla on April 17, 2020, 0350 UTC
On 9024 kHz tonight again, via Khabarovsk SDR, 10+ over s9...
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 17, 2020, 1411 UTC
Shoot. I must have missed it. I checked into the Khabarovsk SDR, probably around 3:10 UTC and it wasn't there. Must have come on just after I logged off.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 17, 2020, 2208 UTC
They're testing something.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Rizla on April 20, 2020, 0448 UTC
"They're testing something."

I think that idea has a lot of merit.

On again tonight, like clockwork, as I write this.

Kiwi in Khabarovsk:
http://khv.proxy.kiwisdr.com:8073/
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Rizla on April 20, 2020, 0502 UTC
Whew, tonight's experiment gone, just like that QRT 20 seconds ago... and the beat goes on.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 20, 2020, 0526 UTC
Yes, on Monday, 20 April, 2020 it was on a bit before 0200 UTC and off at 0501:23 UTC.

So I have still never seen it on a Saturday or Sunday (Asiatic Russian day), but I have seen it on every other day of the week.  There have been one or two days when it did not transmit, and at least one day when I think they substituted a different waveform.  And some days it is on 2 frequencies, other days I never find another freq.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 21, 2020, 0208 UTC
I'm starting to suspect they have a tap on my computer and purposefully don't transmit on days that I am available to listen. I should be sure to post my listening plans here to save you all the trouble of knowing which days to not bother trying.  :)

Okay I take it back. I am listening and signal is on now.

Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 21, 2020, 1356 UTC
I ran TDoA on the signal last night and agree that it is coming from the Khabarovsk area. The Russian Navy transmitter site RAB99 is within the heat map of the signal and seems the most likely transmitter site to me.

(https://lh3.googleusercontent.com/fkqwshw0xftLdWDds_FHzLrHobVh5CUSyeQO5Dep46Vhj_sg5wWi17dH06tHHrmPZD78ItHF-fVzOtByWSw9Zs8cB4p5ctPy7or5bi5SCNUD5R9rD02VAjA_Zc76ptKL-V5SacUMUTuS3Hkxp4B7UNG5S4LD7kPnTz6JNMIynmNu9CxUSs7uel-OG_rKcrJJ2qBMo3L1KFvGEuN6NbLAUtNIJe7aEEJElx0wPoNduzC9kCRlQlPjGk7MKcvxZW3f9N5jmAmyWQGz3E-gmRKCWphERftHH31tXCRRgnqUxtWTdP2T1svMD0i0vc5qAHYUn8QclC7pz8EpjY-D17xhx3XaQzELQdYsiW8jMyz7xC4D_BTVPEZLll_MpHn3pV5jEupdTwGVhhrnqQAovWwWtM8Ifd5otvM0AfAWsnJxw0ey7Mu8g6T-LM2rEsTrBnpN8j7FVAMlDEhYDiVHYLHJSQY7huVowfnTUPOx2nSP5M_w0TZNlDbHokt9CWWMvYLy3QGiNLBlijQpMAbM0CA_TmSX2Zcry3TrLKB09JNl3ZTjyT5guChwPUKiAcxuh2luZahLJ7gSt9sCMGv4MnnexgNYTQBmzAcHxIMC7zjV6QlklaACvcwZ1Xy9xH3LfUhUXlKw98SkhrGysfVFvHZAwpDk5TU29D_BCjV1xQ5UCu1rmsb9gjsLFqi27gXLsiQ=w1015-h443-no)


Since my best heat map showed more of a bullseye on the Bolshekhekhtsirsky Reserve though just to the East though I decided to check it out on Google maps just to see if there was an obvious transmitter site I was missing.

There is a standard microwave radio tower in the middle of the park (likely on a high spot) and something else caught my eye (unrelated to the signal). There are two sites with similar buildings and fencing. They seem excessively heavily guarded. Each site has a series of four closely spaces gated fences and then a fifth perimeter fence around that. This seems excessive for a simple mining operation. My first assumption was an ICBM site but it does not appear to be listed as one online in this area. I wondered if they could just be underground mine entrances but then I would expect large tailings piles.  Any thoughts?

(https://lh3.googleusercontent.com/T4-mgm1e7fakFNr8gA0iiHXFpxfSlgU1-zO0tMemgNakFj8XoPjvOOAvncpxp6MeIACr6to6t_6nRqUFlrRUxhxy759lBJaAqKmAOPH9A1igg5L5C9Vpat_XiDl6BZ7i4NMrtxtLhZVdlwIxIyWLuKn9HaSB8QSvQQW8XFqfcDwGXqT4H77WblDJ_ff49yjxNPWmLhKE5JTQm7ppHWSbyAsKavGi4Wm427qp_n4p6TbIjqaQRV41D15PO7f9mAHFfgsjpuSVdBJ_GYMx0BUBWcVsasbd0GmpCy26y85WwYS3ZTklo-_CxX73OJlIlFoc5z7SPsiwn0WhVHEwnfDBOKw_Ez5UgWMfOJlV_f-q4kbzd6dTZEm5Z-imNW24BSQPj9KKA29BkaS5tumSyVnKSmD3_Iwejoj3qiuyfBrtd1x28DcsDHLGJgx2_KqvtHeXH81JpyxNh4i9lWe7po5Oup4EvbShqr_ud8oeQbDtnZDPPuxlOFmY1Y_IJGml6SikaUbhLVF9wNjcJUX6BlEtoR5yvSaDiWzbXknGB2OqVxjk84UD7ZGUtX5eWf38hrvk1X1iDVULWienN_0vSS_8xCpKRGK9316voMWrqVStI5fEpZyg-VYqhG-zuixVI55KTKDCprmwMlVhwWy3C-I_Fw0FLtdvUADiHZq-RP6QV_AspXXsz6eORaLLwd5wToo=w1051-h893-no)
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: ulx2 on April 22, 2020, 1830 UTC
Seems like this sample is used:

http://www.radiojamming.puslapiai.lt/sound/sound_speechresembling.mp3

There is looped recording with two mixed fragments of female and male voice speeches taken from programs of USSR All-Union Radio (the audio is NOT encrypted).

This sample is presented on Rimantas Pleikys' website, dedicated to deliberate radio jamming, as:
Speech-like signal (USSR 1976-1988, USSR/Poland  1980-1988)
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 22, 2020, 1853 UTC
Seems like this sample is used:

http://www.radiojamming.puslapiai.lt/sound/sound_speechresembling.mp3

There is looped recording with two mixed fragments of female and male voice speeches taken from programs of USSR All-Union Radio (the audio is NOT encrypted).

This sample is presented on Rimantas Pleikys' website, dedicated to deliberate radio jamming, as:
Speech-like signal (USSR 1976-1988, USSR/Poland  1980-1988)

With the above in mind, as well as the tdoa near a naval facility, my rubles are on these guys;
https://planesandstuff.wordpress.com/2019/09/09/murmansk-bn-hf-ew-complex/
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: ulx2 on April 22, 2020, 2144 UTC
The Soviet Union and its East European allies used six types of the jamming audio signals:

1.      To block out the "most anti-Soviet" stations, a wide spectrum electronically generated noise signal was used. RFE/RL, Voice of Israel, and Radio Tirana would experience this type of jamming.

2.      On August 3, 1964, one more source of interference was invented - Radio Mayak program, transmitted in FM mode and heard distorted on domestic receivers - to jam some "grey propaganda" stations such as VOA, BBC, Deutsche Welle, and R. Beijing.

3.      In 1976, Soviets started to use the speech resembling signal. Its advantage was that it conformed to the timbre of the human voice. This jamming sound, which used to be played back from open reel tapes, was composed of two voices of male and female Russian announcers.

4.      A unique case was the Polish service of RFE/RL: from 1971 until 1980 only light instrumental music was employed to jam it, both in clear AM and distorted FM modes.

5.      East Germany aired its domestic radio programs via medium wave transmitters tuned in to several hundred Herz outside of the RIAS frequencies.

6.      Czechoslovakia used the swinging carrier, also known as wobler, AM transmitters to jam RFE/RL.


"Radio Jamming in the Soviet Union, Poland and others East European Countries" by Rimantas Pleikys.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 23, 2020, 0408 UTC
I'm case anyone is curious I found out the reason for the multiple layers of fencing around the buildings in the photo I posted. The site is part of the Korofskiy Nuclear Storage Facility aka Khabarovsk-47. Not a place you want people casually walking into. These buildings were far away from the main buildings and likely contain some pretty nasty materials. Unrelated to the signal being discussed but interesting.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 23, 2020, 1446 UTC
Seems like this sample is used:

http://www.radiojamming.puslapiai.lt/sound/sound_speechresembling.mp3


ulx2, nice find, that does seem to be the source.  I will look at it closer this afternoon to confirm it is the same, but it does appear to be.  Did you discover this yourself or did someone else point it out to you?  I will probably kick out a new video on the signal today or tomorrow and want to credit the right people.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: ulx2 on April 23, 2020, 1733 UTC
Hi, Token. Yes, I found this by myself. I just recalled that I have already heard this sound formerly.
Now I compared this sample with your recording once again, and I'm sure they are identical: I hear the same words.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 23, 2020, 2015 UTC
Hi, Token. Yes, I found this by myself. I just recalled that I have already heard this sound formerly.
Now I compared this sample with your recording once again, and I'm sure they are identical: I hear the same words.

I was sure I had heard that sound (the one on 9024 kHz DSB) before myself, and I had looked at that jammer web site a long time ago.  However, I never connected the two, I just knew the 9024 DSB was familiar in some way.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 24, 2020, 0020 UTC
Hi, Token. Yes, I found this by myself. I just recalled that I have already heard this sound formerly.
Now I compared this sample with your recording once again, and I'm sure they are identical: I hear the same words.

I overlayed spectrograms of the two sources, from the web site and from my recordings, and they are absolutely identical and exactly the same length.  I suspect whoever is transmitting this today actually got the audio from that web site.  The original jammer was not just a 20 second loop like this.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: ulx2 on April 24, 2020, 0105 UTC
I overlayed spectrograms of the two sources, from the web site and from my recordings, and they are absolutely identical and exactly the same length.  I suspect whoever is transmitting this today actually got the audio from that web site.  The original jammer was not just a 20 second loop like this.

T!

I agree. I also think, the audio is not being played from original tape nowadays.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 24, 2020, 0353 UTC
New video up on my YouTube site.  I compare the received audio to the audio form the jammer web site.

https://www.youtube.com/watch?v=pFeGhR3_yXo

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on April 24, 2020, 1522 UTC
Lol, I also put up a new video on this one last night. Gave you credit for finding it of course and put a link to your initial video in the description.

https://youtu.be/tmRqzk7i3JY

Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Strange Beacons on April 24, 2020, 1523 UTC
Nice work figuring this signal out, everyone.

It is this kind of research and dedication that keeps me in love with this forum. 🥰
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 24, 2020, 1538 UTC
Not implying or suggesting any kind of connection at all, but it might be worth noting that Russian Electronic Warfare folks would have recognized / celebrated "День специалиста радиоэлектронной борьбы" (Electronic Warfare Specialist Day) a bit over a week ago, on April 15.  This is a recognition of the importance of a specific early EW event during the Russo-Japanese war in 1904, and in general to the importance of EW to combat capabilities.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on April 27, 2020, 0206 UTC
Going over my logs I realized that I have seen, in the past, Link-11 on all 4 of the frequencies I saw the DSB Oddity on.  I did not see all those freqs in use by Link-11 while the DSB thing was on, but they have all supported Link in the past.  I did see Link-11 on 9022 kHz while the DSB Oddity was on 9024 kHz, so there was a slight overlap there.

But all 4 freqs, 5708, 9008, 9022, and 9024 kHz, have all been tuned freqs for Link-11 in the past.

As Link-11 can be DSB or ISB, it would take a jammer with enough width to cover both sidebands to be effective against Link.  By definition this signal had enough width.  It also did not waist energy on lower audio frequencies where Link-11 would not be.  At a guess, this signal would be at least moderately effective against Link-11.

But I really have a problem believing this looped audio clip from the Internet would be an "official" jam technique.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on April 27, 2020, 1942 UTC
Very nice on link11 tie in. Being the "jammer" in question is possibly naval in origin, using a dsb signal where link11 (used by most every NATO navy) is often sent in isb, the jamming might be at least somewhat effective. While they're not overtly jamming right now the use of the jammer precludes running link11 on those freqs, and allows the jammer to test for typical coverage. But who knows, could be some bored gopniks with an old transmitter.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: KM0NAS on May 01, 2020, 1430 UTC
I do wonder how effective it real is though. If you watch the video I posted I commended on how the signal was right on top of the link 11 signal. There didn't appear to be any attempt to switch the link 11 to another frequency due to interference. So while it has been appearing on those frequencies I haven't seen any effort to avoid the jamming which may indicate it is not effective. Then again...do you purposefully not move when someone is trying to jam to to make it look like it has no effect and thus you make them give up trying because they see you didn't flinch? Who knows. Not us.
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Josh on May 01, 2020, 1823 UTC
Link11 on hf is for los or near los only, not distant over the horizon like typical hf comms, wich is odd because they also have a uhf version of the protocol. I think they cover a cbg with it and that's all they want from it. The link sig might be strong enough for those within los to be unaware if the other signal.
Thus the jammers dilemma, how to jam the jam resistant.

https://us-browse.startpage.com/av/anon-image?piurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F5%2F52%2FUS_Navy_070318-N-5961C-336_Ships_assigned_to_Ronald_Reagan_Carrier_Strike_Group_and_Japan_Maritime_Self-Defense_Force_%2528JMSDF%2529_steam_in_formation_during_a_photo_exercise_%2528PHOTOEX%2529.jpg&sp=1588357370T61451412d57c133541f95231bf971c7deb70dc483eec5a957b89419150757716
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on May 01, 2020, 2210 UTC
Link11 on hf is for los or near los only, not distant over the horizon like typical hf comms, wich is odd because they also have a uhf version of the protocol. I think they cover a cbg with it and that's all they want from it. The link sig might be strong enough for those within los to be unaware if the other signal.
Thus the jammers dilemma, how to jam the jam resistant.

Link-11 is more designed for regional use, beyond LOS but not really long range.  That is why you find it on the frequencies you do, most typically below 15 MHz with a real emphasis below 10 MHz.  It is often used it at beyond LOS, but seldom as far as 600+ miles.  At ranges where you could use the ground wave portion of a 2 to 6 MHz signal.  And yes, you can do Link-11 on VHF and UHF also, but that really is LOS.

Link-11 is for the entire battle group, whatever kind of group it is, and anyone attached to it.  Or it can be simply two (or more) ships independent steaming but supporting each other.  Push the pickets out to screening positions 75+ miles away and the battle group commander, or anyone else in the network, can see the radar / sonar / ESM picture from the pickets.  You can put up the Lamps 3 bird and push it out 200 miles (or more, but then he starts getting short on fuel), and watch his LN-66 picture.  Better yet, when prosecuting an ESM contact you can put the -3 out on a tangential bearing to get another ESM bearing cut on the target, giving you a position plot.  Since the link to the aircraft (this is a dedicated link, not Link-11) is on a tight beam and at UHF the chances of it being intercepted or giving your position away are lessened, so you can end up with a 2D location of a threat while not exposing yourself by lighting up any radars, and often at ranges beyond what your radar could see anyway.  That 2D position then goes out over Link-11 to the rest of the units.  And of course if it is a carrier battle group you can put up an E-2 Hawkeye and push him out several hundred miles with all the same advantages.

You can have the entire group in EMCON, using only passive systems, and one platform active and providing the tactical picture to everyone, obscuring details of who is in your group or where, exactly, you are (assuming you push the active platform outside the group).  This works particularly well with a helo or fixed wing aircraft as the active emitter.  Of course, your Link transmission gives you a way, but it is of limited use as many potential bad guys can't get as much information on an HF signal as VHF and up.

T!
Title: Re: 9024 kHz, DSB, oddity, 03 April, 2020, 0420 UTC
Post by: Token on May 04, 2020, 1326 UTC
Just an FYI, this signal was last on the air on April 24, the day I put up that video on my YouTube channel.  Or at least that was the last time I saw it, and I checked every evening.

Until this morning, May 4.  The signal was observed on 9024 kHz, normal mode and content, before 0300 UTC.  At 0457 UTC it switched from 9024 kHz to 9008 kHz, same mode and content.  It turned off at off 0601 UTC.  I don't believe I have ever seen it shift frequency like that before, although it has used both those frequencies in the past.

Again, these frequencies are "close" to Link-11 freqs.  The entire time the signal was on 9024 kHz there was a Link-11 on 9022 kHz.  Although I did not see it active at the time of the frequency switch, by the time 9008 kHz went off the air there was a Link-11 on 9007 kHz.  I have no idea if the Link on 9007 kHz was there the whole time or not, and if propagation was just preventing me form seeing it at first.

T!