Tones heard

[2alpha56]

I'm an infrequent reader and poster to the RR forums, but a member for many years. I'm sure my scanner and shortwave knowledge is not as robust as all of yours, however, on 3-11-13 at 2130 MST (Utah), I was surfing my shortwave radio and came across a most peculiar broadcast! On frequency 7080 I heard what I can only describe as melodic tones. There were 2 sets of different tones with about a 12 second pause between each set. They were nearly musical. I listened for about 30 minutes and it remained repetitive, no voice, no numbers, no station identification. I checked back at about 2220 MST and the broadcast had stopped. Would anyone know what this is?

Thanks!

 

[ridgescan]

I forgot the proper term for that mode they use but I do know it's ham-kinda sounds like an "evil ice cream truck" to me

 

[2alpha56]

Thank you. That's EXACTLY what it sounds like!

 

[nd5y]

There are several ham radio data modes that use MFSK (multiple frequency shift keying).

 

[ka3jjz]

And as such, off to the amateur data decoding forum this goes...Mike

 

[kc4jgc]

Wirelessly posted (BlackBerry8320/4.5.0.81 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

If you had recorded it and posted it here I'm sure someone could have identified that for you. Off the cuff, I'd hazard a guess at a data mode called MT63. 7080 seems to be a common freq for that mode.

 

[nd5y]

MT63 doesn't sound musical. It sounds almost like white noise. It has 63 BPSK carriers that don't change frequency.

 

[kc4jgc]

Wirelessly posted (BlackBerry8320/4.5.0.81 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

Google was NOT my friend in this instance. I was thinking maybe OLIVIA until I saw all the references to MT63 and 7080. I have heard of a musical sounding mode but don't remember. I do know some other hams that play with hf digital modes; I'll ask one of them.

UPDATE: I was just perusing the forums on QRZ; found a thread asking the same question. One ham said JT65, saying that it sounded "like a demented calliope".

 

[ka3jjz]

A 'demented calliope???' ROTFL!

How about the sound samples found in section 2 of;

HF Digital Decoding - The RadioReference Wiki

HTH...Mike

 

[vagrant]

First things first. 7080 khz is part of the amateur radio band and digital signals can be found on that frequency. Which one you heard that sounded the way it did is a mystery. It could be MFSK, Olivia, or Domino, but that's a long shot. If I had to guess, I'd say Olivia, or JT65 which are more frequent on the bands these days, and melodic. You can listen to some samples and resolve the mystery. WB8NUT - Digital Modes Information Page

You can download Digipan for free and read what you're hearing. It'll probably decode it without having to hook up a line from the radio to the computer. Just put the computer microphone near the radio, but don't overload it with too much volume. Play with it and you'll find the right level.

 

[nd5y]

You can download Digipan for free and read what you're hearing.

Digipan will not decode any of the MFSK type modes mentioned in this thread.

 

[ka3jjz]

Indeed, but MultiPSK will - if you can get over the button-heavy interface (a little busy for my liking)

index

It will even handle a few non-ham modes such as ACARS...Mike