Carlos seeks help identifying signals

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!

Spread the radio love

7 thoughts on “Carlos seeks help identifying signals

  1. neil

    Both of them sound like PSK but listened to in AM mode with some local interference that occasionally makes tones 🙂
    Both would sound more “sensible” in USB
    Next time you hear them, pop over to and see if you can find a local SDR and listen to it on USB, so you know what it sounds like 🙂

  2. Mario

    Listened to both, really don’t have a clue. I agree with Thomas, next time use your BFO or SSB switch so we can hear tones. The first one, if I had to hazard a guess might be a weak RTTY station. When listening to digital modes like RTTY, FAX, ALE, SITOR, etc., always have your rcvr in SSB mode.


Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.