HFU HF Underground

Loggings => Utility => Topic started by: Teotwaki on July 15, 2019, 0128 UTC

Title: 11,175 KHz data stream
Post by: Teotwaki on July 15, 2019, 0128 UTC
01:29Z 15July2019

Possibly someone threw the wrong switch?

I heard a few normal USAF voice messages and next thing this odd data signal pops up. Within the USB channel there are three main peaks appearing on my waterfall display

Title: Re: 11,175 KHz data stream
Post by: Josh on July 15, 2019, 1850 UTC
USAF has a legacy TFSK (triple fsk) mode, can't recall the name, shows up every few months.
I've seen where a naoc flight will be expecting a data sig on hf and hfgcs will provide it, sometimes even on 11175. This is odd because of all the traffic triple one sees, but a general gets what a general wants I suppose. Normally they use a discreet like 11220 or 11244 for such.