HFU HF Underground

Loggings => Other => Topic started by: BoomboxDX on June 08, 2013, 0908 UTC

Title: UNID rhythmic data pulses, poss. Jammer; 11930 khz, 0554z, 6/8/2013
Post by: BoomboxDX on June 08, 2013, 0908 UTC
Tuned through the 25 meter band, heard the data pulses again, on top of a carrier.

This time they were on 11930 khz, and I could just barely hear some audio way in back of them, sounded like a woman, and the pace and tone was non-English, poss. Asian -- but because the audio was unreadable, I'm just making a complete guess here, from the tones of the voice. 

I'm wondering if this isn't some sort of jammer.

Were still on the frequency during recheck at 0641z, audio was a tiny bit stronger behind the pulses, still unreadable.

Looking at the SW schedules, nothing is usually scheduled here in this time slot that would be jammable. The only thing I can find scheduled is R. Belarus.

The data pulses didn't really sound like LINK-11, as I noted in my previous post on this sound.  Unless there's an 'idle' LINK sound, like when RTTY is sort of idling, it just puts out blips....  but I don't know enough about sounds to venture a guess.
Title: Re: UNID rhythmic data pulses, poss. Jammer; 11930 khz, 0554z, 6/8/2013
Post by: glimmer twin on June 14, 2013, 0315 UTC
Hi Boombox, I think you heard a Cuban jammer against Radio Marti (as per Aoki). Radio Marti is on 11930 from 14:00 to 24:00 utc

here is the current Aoki listing


http://www1.m2.mediacat.ne.jp/binews/use/bia13.txt

I use ctrl F and then enter the frequency for easy looking up of freqs.

BTW, Just because the offending station is not on air doesn't mean the Cuban jammer won't be there. They have been known recently to jam frequencies that Radio Marti used last year. At least the Chinese Jammers check at the top of the hour to see if the offending station is still on air.
Title: Re: UNID rhythmic data pulses, poss. Jammer; 11930 khz, 0554z, 6/8/2013
Post by: BoomboxDX on June 14, 2013, 1051 UTC
Many thanks for the info, Glimmer Twin, it sounded like jamming this time. Maybe the mystery is now solved.

I wasn't aware of Cuba's jamming techniques.... that's good to know.