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Author Topic: Mayday transmission on 6689 khz USB 15:27 UTC-12 March(incl SDR IQ & AUDIO .wav)  (Read 3633 times)

Offline jasmine

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i was listening to hear what was coming in on 6689 khz USB as that was no frequency i had associated with air traffic and i often pick up interesting things in the 6-7 Mhz range out of asia, the pacific, australia, new zealand and even the indian ocean most mornings. today i heard something different.

can anyone tell me what this is? i think the language spoken is russian with the only english word heard: "Mayday! Mayday! Mayday!" 
there are two recordings which i recorded straight as IQ .wavs from SDRuno. the first one is what i think is the "mayday" transmission. the second is a transmission i recorded not long before it to try to figure out what language was being spoken.

Recording 1 "Mayday!": https://drive.google.com/file/d/11iolyMq9xru-tZRx15M_tUzhF1oOWm9l/view?usp=sharing
Recording 2 Previous recording: https://drive.google.com/file/d/12nltkwKvY6evkT69zNprklV_LSJ8Y1Nz/view?usp=sharing

Was this a plane or ship in distress?
« Last Edit: March 20, 2020, 0220 UTC by jasmine »
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Offline nickcarr3151

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This must be a proprietary format for SDRuno.  I'm hearing only static bits.
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Offline jasmine

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This must be a proprietary format for SDRuno.  I'm hearing only static bits.

it's not proprietary. it's not an audio wave but an IQ (spectrum) recording.

download any SDR application (SDR#, HD SDR, etc) and open the .wav with it and tune to 6689 khz USB
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Offline nickcarr3151

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it's not proprietary. it's not an audio wave but an IQ (spectrum) recording.

Why not just provide an audio clip?  Just my .02 but you'll probably get more responses with it.
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Offline jasmine

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because there is no ability to just record audio in SDRUno and because an IQ recording is superior. one can do their own processing on the signal. besides, it's 2020, don't most people here have SDRs? it's not like you need one in order to download the software. SDR apps are free.
« Last Edit: March 12, 2020, 2106 UTC by jasmine »
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Offline kalvados

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Recording 1 "Mayday!":
06542 calls Moda:
- Мода, Мода, Мода я 06542, приём

The Russian word Мода - Fashion is consonant with Mayday

Recording 2 Previous recording:
- Крутов-18, Крутов-18 я 06542, приём

PS:
06542 probably Tu-142 (NATO codification: Bear-F - Soviet and Russian long-range anti-submarine aircraft)
« Last Edit: March 19, 2020, 0203 UTC by kalvados »

Offline ChrisSmolinski

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because there is no ability to just record audio in SDRUno and because an IQ recording is superior. one can do their own processing on the signal. besides, it's 2020, don't most people here have SDRs? it's not like you need one in order to download the software. SDR apps are free.

I'm a huge fan of SDRs, but as nickcarr3151 pointed out, virtually no one is going to jump through all these hoops to listen to it. Why not play your IQ recording through a virtual audio device, record as a WAV or mp3 file, and post a link to that. Then we can all listen  :)
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Offline Strange Beacons

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Quote
Why not play your IQ recording through a virtual audio device, record as a WAV or mp3 file, and post a link to that. Then we can all listen  :)

Yes, Audacity is a free, open source audio program. I use it to record things off of my computer all the time. I agree that the OP would get a much better response by providing a .wav or .mp3 file.
« Last Edit: March 18, 2020, 2115 UTC by Strange Beacons »

Offline Josh

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https://voca.ro/gwLYyJ0JnBP
a few secs of silence at the start
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Offline Pigmeat

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Jasmine, you just stepped into dangerous territory with that SDR comment. Real radios have knobs.

Offline kalvados

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I don’t see a problem - download two files IQ and open them in HDSDR.
But in this case, I also do not understand why IQ files are needed, audio files are much simpler.
« Last Edit: March 19, 2020, 0437 UTC by kalvados »

Offline jasmine

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Ok i found that SDR# does allow for audio recording so i pulled the IQ wavs into there and made these two audio recordings.

Recording 1:
https://drive.google.com/file/d/1gn0hX3BWry5oreKgJ1IgMO0EpvbsSxOS/view?usp=sharing

Recording 2:
https://drive.google.com/file/d/1hcQIa4fMm-1YPgercTfnKcIdgGciiRiC/view?usp=sharing
« Last Edit: March 20, 2020, 0216 UTC by jasmine »
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Offline kalvados

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jasmine

Recording 1 "Mayday!":
06542 calls Moda:
- Мода, Мода, Мода я 06542, приём

The Russian word Мода - Fashion is consonant with Mayday

Recording 2 Previous recording:
- Крутов-18, Крутов-18 я 06542, приём

PS:
06542 probably Tu-142 (NATO codification: Bear-F - Soviet and Russian long-range anti-submarine aircraft)

sorry for repeating

Offline jasmine

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thank you kalvados!
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Offline Josh

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"Мода, Мода, Мода я 06542, приём" being translated is "mayday mayday mayday, I'm 06542, copy". Russian naval air employs 5 digit ids to aircraft, dunno if this is related to their tail numbers or a per mission id.

While I doubt this transmission is related, last week USAF and CANFORCE fighters escorted Russian sub hunters as they skirted the Alaskan coast.
https://defpost.com/norad-f-22s-cf-18s-intercept-two-russian-tu-142-aircraft-entering-alaskan-adiz/

This is the bird in question;
https://en.wikipedia.org/wiki/Tupolev_Tu-142

We have sub hunters too;
https://en.wikipedia.org/wiki/Lockheed_P-3_Orion
https://en.wikipedia.org/wiki/Boeing_P-8_Poseidon
« Last Edit: March 20, 2020, 2320 UTC by Josh »
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