Many thanks to SWLing Post contributor, Carlos Latuff, who writes:
Attached are two different recordings.
Both made in South Brazil.
– Florianópolis, 26/11/2019, 19h13 (Brasilia time) 12015 kHz
– Porto Alegre, 12/12/2019, 20h11 (Brasilia time) 7455 kHz
Searching on the Web I found these two frequencies related to US Navy NATO RTTY station STANAG 4481:
Are you able to confirm this?
Thanks for your inquiry, Carlos! Unfortunately, I cannot confirm this. If your radio had been in SSB mode, it would have made the RTTY pop out and we could have perhaps confirmed at least the RTTY mode with FLDIGI. I’m hoping a savvy SWLing Post reader can help you ID these transmissions. Please comment!