RTTY on 11175

[zack6849]

Has anyone noticed RTTY (or something that sounds similar) on 11175? Picking it up from west central florida at 6 PM, usually at around the top of the hour they have some kind of message, but it seems that they've been broadcasting RTTY for a solid 10 minutes or so, I've never seen that before, but I don't listen to HFGCS super often, anyone know what that's about?

Edit: now they're doing a normal EAM and also hearing the RTTY sounding signal at the same time?

 

[dlwtrunked]

The FSK RTTU is centered on 11177 kHz. It appears to be 850 Hz shift 75 Bd and is encrypted. This indicates a probably NATO origin. It has been reported to be Diego Garcia in the past.

 

[NEET]

Has anyone noticed RTTY (or something that sounds similar) on 11175? Picking it up from west central florida at 6 PM, usually at around the top of the hour they have some kind of message, but it seems that they've been broadcasting RTTY for a solid 10 minutes or so, I've never seen that before, but I don't listen to HFGCS super often, anyone know what that's about?

Edit: now they're doing a normal EAM and also hearing the RTTY sounding signal at the same time?

These things can go on for hours or even days. They appear to have some degree of coordination HFGCS voice broadcasts. It's possible the HFGCS operators are in direct control of them. Whether or not the following occurs may vary based on parameters I'm unsure of, but there are many instances where the broadcast stops prior to an EAM transmission, and resumes afterward. In other cases, the signal might be ongoing on 4724 kHz (i.e. centered on 4725 or whatever it might be, but still audible on 4724 kHz USB), but you will still hear it in the background of the 11175 kHz broadcast, etc.

(I feel like it is one of the bigger oversights when it comes to "HFGCS coverage" that people don't document the time and duration of these broadcasts. It is of course a hobby, so one has to manage their expectations.)