3470.0 KHz scrambled comms

nexus · #1 (**permalink**) 03-04-2009, 09:57 PM

I've been tuning around and found some very active communications tonight on 3470.0 khz but the only thing is they're all scrambled. I've never heard voice-inversion used on HF before, but have heard it used on a local police department from time to time.

I use to have a motorola 900mhz cordless phone that used the same technology. I'm curious if anyone on here knows who uses 3470.0 It can't be MARS because they're all in the open. And I didn't think any US military used this kind of encryption. So who could it be I'm hearing?

I made a short recording in mp3 format and have put it on here so everyone could hear what I'm hearing. It's a bit weak in the noise but you can tell its voice-inversion.

You can listen to it here http://www.nexusradio.us/audio/3470.mp3

zz0468 · #2 (**permalink**) 03-04-2009, 11:54 PM

Are you sure you weren't just listening to it in the wrong sideband?

brandon · #3 (**permalink**) 03-05-2009, 12:05 AM

Possibly Harris Analog Voice Security? I have heard similar scrambling on the 3MHz ranges for years.
Here are audio samples of encryption used on HF
http://www.signals.taunus.de/TABLES/VOCODER.HTML
I like the Sailor "Cry 2001" scrambling

kb2vxa · #4 (**permalink**) 03-05-2009, 08:43 AM

It would be nice without the digital artifacts giving me ear bleed. Most likely you were set to LSB and FYI, the only radio service that uses LSB is Amateur and only on the 160, 80 and 40M bands, everything else is USB. 3470 is an air route frequency, South East Asia (SEA), 3473 (your dial could be a little off) is Middle East (MID), 3467 is Africa (AFI) and South Pacific (SP).

nexus · #5 (**permalink**) 03-05-2009, 09:05 AM

Quote:

Originally Posted by zz0468

Are you sure you weren't just listening to it in the wrong sideband?

I knew someone was going to ask me that! I was not on the wrong side band. It's USB and even if it wasn't I tried both.

nexus · #6 (**permalink**) 03-05-2009, 09:11 AM

Quote:

Originally Posted by kb2vxa

It would be nice without the digital artifacts giving me ear bleed. Most likely you were set to LSB and FYI, the only radio service that uses LSB is Amateur and only on the 160, 80 and 40M bands, everything else is USB. 3470 is an air route frequency, South East Asia (SEA), 3473 (your dial could be a little off) is Middle East (MID), 3467 is Africa (AFI) and South Pacific (SP).

USB was the mode I was in. I know what I'm doing thank you. and FYI there are some other users of HF outside of the amateur radio bands that use LSB. Mostly maritime operations, and I have monitored some Mars nets in the 4mhz segment on LSB. Also you left out the 60 meter band. It's the 160, 75, 60, and 40 meter bands that use LSB, and 20, 15, 12, and 10 meters that use USB. Of course this isn't set in stone, I've heard plenty of hams in the extra portions operate LSB on 20 and 15 meters.

Anyhow I know what I'm doing, I know how utility/military stations operate versus ham radio. Bottom line, i checked LSB and USB and had the same results. The spectrum analyzer has it on 3470.0

so i take it you've not heard any traffic on that frequency before?

nexus · #7 (**permalink**) 03-05-2009, 09:12 AM

moderator Please Delete This Thread

zz0468 · #8 (**permalink**) 03-05-2009, 09:20 AM

Quote:

Originally Posted by nexus

I'm not stupid.

I never said you were, but you better believe I'll be watching for that next time.

Quote:

Originally Posted by nexus

I know how to properly tune in and zero beat on someone's frequency. I checked both LSB and USB and had the same results.

Knowing that would have been useful.

Quote:

Originally Posted by nexus

I posted the audio for a reason. If you'd listen you'd realize it's some kind of voice-inversion scrambling.

I DID listen to it. Ever hear a foreign language, slightly detuned and in the wrong sideband?

It's an Air route frequency, like Warren said, for Southeast Asia. Not a place one would expect to hear voice inversion scrambling. But it could happen...

zz0468 · #9 (**permalink**) 03-05-2009, 09:22 AM

Quote:

Originally Posted by nexus

moderator Please Delete This Thread

Why are you getting so bent out of shape for such an innocuous suggestion as trying the other sideband? Cripes. Get your chonies unbunched and move on.

Sounds like someone needs a little nap.

Spec · #10 (**permalink**) 03-05-2009, 09:36 AM

In the past I have monitored commercial fisherman using phase inversion on "out of band" frequencies between boats of the same fleet. Often they are passing info about how well certain areas are doing. This may be what you are hearing.

blantonl · #11 (**permalink**) 03-05-2009, 09:45 AM

That's exactly what I was going to say... I'd bet it's speech inversion scrambling by fisherman.

rankin39 · #12 (**permalink**) 03-05-2009, 11:56 AM

Back in the 1950s international point-to-point telephone calls on shortwave used to use voice inversion for a little privacy. I verified one test transmission like that coming from Guam at the time. That service is mostly gone now, but I imagine inversion is still used a little by people like fishermen with low-level security needs.
Bob, WoNXN

kb2vxa · #13 (**permalink**) 03-07-2009, 02:16 AM

I try to help and get snotted all over? Well if you knew what you were doing you never would have posted the question Mister Know It All! May as well lock the thread, this is going the usual nowhere.

Hooligan · #14 (**permalink**) 03-09-2009, 11:59 PM

Kinda has a LINCOMPREX sort of tonal quality to it, but the voice cadences of the communication makes it sound like a personal conversation/BS'ing as opposed to anything official by trained communicators. While it probably is just something like fishermen bootlegging with low-grade crypto, it's still possible that it is some sort of point-to-point link not using any communications security other than an exotic mode.

CharlesDom · #15 (**permalink**) 03-10-2009, 03:08 AM

nexus it's ok you're not going crazy. I hear this all of the time but for some reason it's mostly on the weekend. I believe it to military scrambled comms. One Saturday I followed them from one frequency (ATC) to the next. If not military then it has something to do with testing comms for air traffic.

It's not your radio and it has nothing to do with incorrect tuning. Believe me, I tried everything when I first heard it. But then I realized that they were jumping from freq to freq used by ATC in the Northern Pacific.

immelmen · #16 (**permalink**) 03-10-2009, 04:20 AM

Quote:

Originally Posted by nexus

Also you left out the 60 meter band. It's the 160, 75, 60, and 40 meter bands that use LSB, and 20, 15, 12, and 10 meters that use USB. Of course this isn't set in stone, I've heard plenty of hams in the extra portions operate LSB on 20 and 15 meters.

Prolly just a typo, 60m is legal for USB only per FCC...

kb2vxa · #17 (**permalink**) 03-11-2009, 05:20 AM

There is no rule governing which sideband Amateurs must use except for 60M. LSB is only a holdover from the days when generating it on those bands was a transmitter design function, now it's simply a habit. Once upon a time I heard two groups using a single 40M frequency, one on LSB and the other on USB. Don't ask why, my guess is because they were Canadians. (;->)

Re: 60M
The new, restricted, amateur allocation on 5 MHz has been opened to hams as of July 3, 2003.

This is a unique band, with operation limited to five specific channels, on which hams may operate only upper sideband with a maximum bandwidth of 2.8 kHz and a maximum effective radiated power of 50 watts. In order to operate on the assigned center frequencies of:
5332
5348
5368
5373
5405
hams should tune their radios in USB mode to the following readings:
5330.5
5346.5
5366.5
5371.5
5403.5
kHz in order to compensate for the single sideband offset from center frequency.

VernM · #18 (**permalink**) 04-07-2009, 02:51 PM

If you guys ever get over one-upping each other and get back to the posted topic, my guess is digital and Spanish-speaking. I hear it here at home on 3733 in the mornings behind our local radio group and noted while in lower Texas in December and Feb. that it was louder in volume there while still a ways away Like several hundred miles, I'd bet.

psr600md · #19 (**permalink**) 04-08-2009, 12:11 PM

Quote:

Originally Posted by nexus

I've been tuning around and found some very active communications tonight on 3470.0 khz but the only thing is they're all scrambled. I've never heard voice-inversion used on HF before, but have heard it used on a local police department from time to time.

I use to have a motorola 900mhz cordless phone that used the same technology. I'm curious if anyone on here knows who uses 3470.0 It can't be MARS because they're all in the open. And I didn't think any US military used this kind of encryption. So who could it be I'm hearing?

I made a short recording in mp3 format and have put it on here so everyone could hear what I'm hearing. It's a bit weak in the noise but you can tell its voice-inversion.

You can listen to it here http://www.nexusradio.us/audio/3470.mp3

sounds like fishermen,